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The  Diffusion  of  Crude  Petroleum 
through  Fuller's  Earth. 


DISSERTATION. 

SUBMITTED  TO  THE  BOARD  OF  UNIVERSITY  STUDIES  OF 

THE  JOHNS  HOPKINS  UNIVERSITY  IN  CONFORMITY 

WITH  THE  REQUIREMENTS  FOR  THE  DEGREE  OF 

DOCTOR  OF  PHILOSOPHY. 


By 


OSCAR  ELLIS  BRANSKY, 


EASTON,  PA.: 

ESCHBNBACH  PRINTING  COMPANY 
1911. 


The  Diffusion  of  Crude  Petroleum 
through  Fuller's  Earth* 


DISSERTATION. 

SUBMITTED  TO  THE  BOARD  OF  UNIVERSITY  STUDIES  OF 

THE  JOHNS  HOPKINS  UNIVERSITY  IN  CONFORMITY 

WITH  THE  REQUIREMENTS  FOR  THE  DEGREE  OF 

DOCTOR  OF  PHILOSOPHY. 


By 


OSCAR  ELLIS  BRANSKY. 


EASTON,  PA.: 

ESCHENBACH  PRINTING  COMPANY 
1911. 


ACKNOWLEDGMENT. 

To  President  Remsen,  and  Professors  Morse,  Jones,  Renouf, 
and  Acree,  the  author  is  greatly  indebted  for  valuable  instruc- 
tion in  the  lecture  room  and  laboratory.  The  author  wishes, 
in  particular,  to  express  his  gratitude  to  Dr.  Gilpin,  under 
whose  guidance  this  investigation  has  been  pursued,  and  to 
Dr.  Day,  of  the  United  States  Geological  Survey.  Thanks 
are  also  due  to  Prof.  Swartz  for  important  suggestions. 


222271 


CONTENTS. 

Acknowledgment : 3 

Introduction 5 

Object  of  this  Investigation 14 

Experimental 14 

I.  Relative  Amounts  of  Oil  Lost  in  Heated  and  Unheated 

Fuller's  Earth 14 

II.  The   Diffusion   of    Benzene    in    Solution   through    Fuller's 

Earth 18 

III.  The  Fractionation  of  Crude  Petroleum 31 

IV.  Chemical  Examination  of  the  Fractionated  Oils 49 

V.  Selective  Action  of  Fuller's  Earth 53 

Summary 56 

Biographical 58 


The  Diffusion  of  Crude  Petroleum  through  Fuller's 

Earth* 


INTRODUCTION.1 

It  is  a  well-established  fact  that  the  petroleum  obtained 
from  the  sandstones  of  the  Upper  Devonian  and  Mississippian 
periods,  generally  known  as  the  Pennsylvania  oil,  differs 
markedly  from  the  natural  oil  found  in  the  Trenton  limestone, 
usually  designated  as  the  Ohio  oil,  or  Trenton  limestone  oil. 
Both  of  these  oils,  in  turn,  are  distinctly  different  from  the 
petroleum  occurring  in  the  loose  sands  and  soft  shales  of 
California.  The  unconsolidated  tertiary  clays,  sands,  and 
gravels  in  the  southern  United  States,  particularly  in  Texas, 
yield  another  variety  of  petroleum,  characterized  by  proper- 
ties more  or  less  different  from  any  of  the  preceding  oils. 

Not  only  do  these  differences  exist  between  oils  found  in 
separate  regions,  but  extreme  variations  in  color  and  specific 
gravity,  as  well  as  in  chemical  composition,  often  occur  between 
those  of  neighboring  localities.  On  the  other  hand,  close  re- 
semblances abundantly  occur  between  petroleums  of  sections 
widely  removed  from  each  other.  Some  of  the  South  Amer- 
ican and  many  of  the  European  oils,  for  instance,  have  been 
found  to  possess  properties  very  similar  to  those  of  the  oils 
of  the  southern  United  States;  while  the  oil  from  the  Cornifer- 
ous  limestone  of  Canada  closely  resembles  the  Ohio  petroleum. 

These  variations  in  the  oils  of  the  United  States  and  other 
countries  have  been  carefully  studied  by  many  investigators. 
Such  noted  workers  as  Warren,  Storer,  Mabery,  Pelouze, 
Cahours,  Schorlemmer,  Beilstein,  Markownikoff,  Kngler,  and 
Kurbatoff  have  devoted  their  lives  to  this  subject.  The  ques- 
tion that  naturally  arises  in  connection  with  these  variations 
is:  Are  these  differences  fundamental?  Is  the  Pennsyl- 
vania petroleum  as  distinctly  different  from  the  Ohio  oil  as 
one  chemical  compound  is  from  another?  In  answer  to  these 

1  This  research  was  aided  by  a  grant  received  from  the  C.  M.  Warren  Committee 
of  the  American  Academy  of  Arts  and  Sciences. 


b 

questions,  the  following  extract  from  a  paper  read  by  Mabery1 
in  1903  before  the  American  Philosophical  Society  is  of  con- 
siderable importance:  "Now,  after  years  of  arduous  labor, 
I  have  reached  the  conclusion  that  petroleum  from  whatever 
source  is  one  and  the  same  substance,  capable  of  a  simple 
definition — a  mixture  of  variable  proportions  of  a  few  series 
of  hydrocarbons,  the  product  of  any  particular  field  differing 
from  that  of  any  other  only  in  the  proportion  of  the  series 
and  the  members  of  the  series."  The  evidence  supporting 
this  declaration  has  been  and  is  accumulating  constantly, 
and,  at  the  present  time,  this  view  is  generally  accepted. 

If  petroleum,  then,  is  one  and  the  same  substance,  how  can 
the  extreme  variations  between  the  American  oils  be  ex- 
plained? Were  the  causes  operating  in  the  formation  of  the 
Pennsylvania  oil,  almost  barren  of  sulphur  and  nitrogenous 
bodies,  different  from  those  acting  in  the  production  of  the 
sulphur-bearing  oils  of  Ohio,  or  the  heavy  sulphur  and  nitrog- 
enous oils  of  California? 

To  account  for  the  formation  of  crude  petroleum,  two  views, 
as  is  well  known,  the  organic  and  inorganic,  have  been  ad- 
vanced. The  Pennsylvania  oil,  according  to  these  theories, 
may  have  been  formed  either  from  organic  or  inorganic  sub- 
stances, or  from  both.  It  is  as  yet  impossible,  however,  to 
state  conclusively  from  which  of  these  sources  the  oil  was  de- 
rived. It  is  apparent,  therefore,  that  the  differences  between 
the  Pennsylvania  and  the  Ohio,  Texas,  and  California  oils 
cannot  be  explained  upon  the  assumption  that  the  former 
was  formed  from  organic  remains,  while  the  latter  were  pro- 
duced from  inorganic  matter,  or  vice  versa.  If,  however, 
crude  petroleum  is  organic  in  origin,  it  may  have  been  formed 
either  from  vegetable  or  from  animal  remains.  The  follow- 
ing discussion  is  based  upon  the  assumption  that  the  above- 
mentioned  oils  were  derived  from  an  organic  source. 

It  has  been  suggested  that  the  differences  between  these 
oils  may  be  accounted  for  by  assigning  a  vegetable  origin  to 
the  Pennsylvania  oil,  and  an  animal  origin  to  the  others. 

»  P.  Am.  Phil.  Soc.,  1903. 


Mabery1  states  that  "It  would  seem  that  the  small  propor- 
tion of  these  bodies2  in  the  Pennsylvania  oil,  as  compared  with 
the  larger  proportions  in  the  limestone  oils  and  California  oils 
should  be  strong  evidence  in  favor  of  a  different  origin,  that 
the  Pennsylvania  oil  came  from  organic  vegetable  remains, 
which  should  permit  of  the  small  amounts  of  sulphur  and 
nitrogen  compounds  from  this  class  of  oils."  Newberry, 
Peckham,  Orton,  and  other  geologists  also  favor  the  view 
that  the  Pennsylvania  oil  is  of  vegetable  origin,  and  is  derived 
from  the  organic  matter  of  the  bituminous  shales  of  the  Devo- 
nian period. 

The  facts  which  have  led  to  the  association  of  this  oil  with  a 
vegetable  source  are,  first,  that  the  oil  is  of  a  different  charac- 
ter from  the  limestone  oils  of  Ohio,  and  those  of  Texas  and 
California;  second,  that  the  Pennsylvania  petroleum  is  found 
in  strata  that  bear  but  few  fossils;  third,  the  belief  that  the 
Chemung  and  immediately  overlying  formations  are  barren 
of  animal  organic  remains;  fourth,  the  existence  of  large  quan- 
tities of  microscopic  fossils,  whose  origin  many  believe  to  be 
vegetable,  in  the  black  shales  of  the  Lower  and  Middle  Devo- 
nian periods,  to  which  formations  many  investigators  are  in- 
clined to  refer  the  origin  of  the  Pennsylvania  oil. 

It  is  generally  recognized  that  the  Pennsylvania  oil  differs 
markedly  from  the  Ohio,  Texas,  and  California  oils.  Inves- 
tigation has  shown  that  the  former  contains  a  much  larger 
proportion  of  the  paraffin  hydrocarbons,  and  a  much  smaller 
percentage  of  benzene  and  unsaturated  hydrocarbons  and 
sulphur  and  nitrogenous  bodies,  than  the  latter  oils.  It  is 
further  generally  admitted  that  the  Pennsylvania  oil  was  not 
formed  in  situ.  These  two  facts  have  aided  strongly  in  as- 
signing a  vegetable  origin  to  this  oil.  To  what  strata,  then, 
should  the  source  of  the  oil  be  referred?  The  great  coal  forma- 
tions of  Pennsylvania,  lying  above  the  Chemung,  seem,  at  a 
first  glance,  to  offer  a  solution  of  this  problem.  It  is  a  notable 
fact,  however,  that  these  formations  have  not,  up  to  the 
present  time,  been  connected,  either  chemically  or  geologically, 
with  the  Pennsylvania  oil.  The  possibility  exists,  however, 

1  P.  Am.  Phil.  Soc..  1903. 

2  Reference  is  made  to  the  sulphur,  nitrogen,  and  oxygen  compounds  in  petroleum. 


that  it  was  formed  from  vegetable  remains  in  the  Carbonifer- 
ous formations  above,  and  that  then,  by  downward  diffusion, 
it  reached  its  present  position  in  the  Chemung.  This  view 
rests  upon  the  physical  fact  that  a  liquid  diffuses  by  the  force 
of  -capillarity  in  all  directions,  downward  as  well  as  upward. 
Little  attention  has  been  given  to  this  possibility,  but  it  seems 
to  deserve  a  very  careful  study.  Owing,  however,  to  the  uni- 
versal association  of  water  under  hydrostatic  pressure  with 
natural  oil  and  gas,  the  migration  of  the  latter  is  generally 
upward.  This  fact  is  attested  by  the  accumulation  of  oil 
in  anticlinal  folds  when  water  is  present,  and  by  the  existence 
of  the  remarkable  gushing  oil  wells.  That  the  Pennsylvania 
oil,  if  not  formed  in  situ,  ascended  to  its  present  location  seems, 
therefore,  more  probable. 

In  what  strata  below  the  Chemung,  then,  was  the  oil  origi- 
nally produced?  It  has  been  previously  mentioned  that  a 
number  of  investigators  refer  the  source  of  the  oil  to  the  black 
shales  of  the  Lower  and  Middle  Devonian  periods.  The  or- 
ganic matter  of  these  shales  is  composed  largely  of  micro- 
scopic sporangites,  which  suggest  the  existence,  according  to 
Orton,  of  masses  of  floating  vegetation,  or  Sargasso  seas. 
According  to  this  view,  the  origin  of  the  Pennsylvania  oil  is 
vegetable  in  character,  and  its  primitive  abode  was  in  the 
shales  of  the  Devonian  age  lying  below  the  Chemung  sand- 
stone, to  which  it  ascended  under  the  influence  of  natural 
agencies.  Another  origin,  animal  in  character,  may  be  as- 
signed to  this  oil.  This  view  is  that  the  oil  was  formed  in 
the  fossil-bearing  strata  of  the  Chemung  age,  and  that  it 
diffused  to  the  sandstone  reservoirs  in  which  it  is  now  found, 
and  that  during  such  a  diffusion  its  original  character  was 
changed.  Prof.  C.  K.  Swartz,  of  the  Johns  Hopkins  Uni- 
versity, who  has  made  a  critical  study  of  the  Chemung  strata 
in  Maryland,  informs  us  that  fossil  remains  exist  in  considera- 
ble abundance  in  the  strata  of  this  age  in  Maryland  and  ad- 
joining areas.  In  Pennsylvania,  the  corresponding  strata 
have  been  found  to  bear  many  fossils.  It  is  possible  that  the 
oil  formed  in  these  strata,  and  then  diffused  to  the  strata  in 
which  it  now  exists  and  which  are  barren  of  fossil  remains. 


The  evidence  accumulated  in  this  investigation  seems  to 
show  that  it  is  not  necessary  to  assign  a  vegetable  origin  to 
the  Pennsylvania  oil  to  explain  the  differences  between  it 
and  the  oils  of  Ohio  and  California.  It  is  clear  from  the  re- 
sults of  this  and  other  investigations  that,  when  such  oils  as 
those  of  Ohio  and  California  and  Texas,  which  seem  to  be  of 
animal  origin,  are  allowed  to  diffuse  through  such  porous 
media  as  fuller's  earth,  they  yield  oils  very  similar  to  those  of 
Pennsylvania.  By  assuming,  therefore,  that  the  Pennsylva- 
nia oil  migrated  from  some  primitive  source,  in  which  it  may 
have  been  formed  from  animal  remains,  through  shales,  lime- 
stones, and  sandstones,  its  peculiar  character  can  be  under- 
stood. 

Whatever  the  original  home  of  the  oil,  it  seems  probable 
that  it  migrated  to  its  present  location  from  some  place  be- 
low. It  is  with  the  changes  occurring  in  crude  petroleum 
as  a  result  of  such  a  migration  through  porous  strata  that  the 
present  investigation  is  primarily  concerned. 

In  1897,  Dr.  David  T.  Day,1  from  his  own  observations, 
and  those  of  Dr.  John  N.  MacGonigle,  proposed  the  view  that 
the  Pennsylvania  oil,  at  some  past  time,  possessed  properties 
very  similar  to  those  of  the  Ohio  oil,  but  that  in  its  migration 
to  its  present  abode  from  regions  below,  its  character  was 
changed  to  its  present  condition. 

Guided  by  this  view,  he  conducted,  in  the  laboratories  of 
the  United  States  Geological  Survey,  an  investigation  into 
the  changes  occurring  in  crude  petroleum  when  allowed  to 
diffuse  through  porous  media,  such  as  fuller's  earth.  He 
demonstrated  clearly  that  an  oil  resembling  the  light  Pennsyl- 
vania oil  could  be  readily  produced  in  the  laboratory  from 
the  heavier  crude  Ohio  oil.  Glass  tubes  were  packed  firmly 
with  the  dry  earth,  through  which  the  crude  oil  diffused  by 
its  own  force  of  capillarity.  From  the  earth  of  the  upper 
sections  of  the  tubes,  very  light,  in  some  cases  colorless,  oils 
were  liberated  by  treatment  with  water;  from  the  earth  of 
the  lower  sections  of  the  tubes,  much  darker  and  heavier  oils 
were  obtained. 

i  P.  Am.  Phil.  Soc.,  1897. 


10 

It  will  be  observed  that  the  fractionation  is  effected  entirely 
by  capillarity;  oils  with  different  surface  tensions  rise  with 
different  velocities  through  the  capillary  openings,  such  as 
the  fine  interstices  and  minute  pores  of  the  fuller's  earth.  A 
separation  of  the  various  constituents  making  up  the  com- 
plex of  any  one  oil  is  thus  produced.  The  view  once  held 
that  this  phenomenon  is  chemical  was  clearly  disproved  by 
Kngler  and  Albrecht1  in  1901,  and  later  by  other  investiga- 
tors. 

Any  medium,  therefore,  sufficiently  fine-grained  and  porous 
to  afford  capillary  spaces  causes  a  separation  of  the  con- 
stituents of  any  mixture,  provided  they  possess  different 
surface  tensions.  The  compact  sandstones,  shales,  and  lime- 
stones that  recur  in  many  cycles  throughout  the  earth's  crust 
present  an  excellent  medium  for  the  separation  of  the  con- 
stituents of  such  a  complex  mixture  as  petroleum.  The 
force  of  capillarity,  assisted  by  the  hydrostatic  pressure  of 
the  water  occurring  in  the  interior  of  the  earth,  acting  over 
vast  periods  of  time,  is,  it  seems  safe  to  state,  sufficiently 
powerful  to  transport  the  oil  from  the  lower  regions  to  those 
above.  That  the  condition,  therefore,  to  cause  such  a  migra- 
tion, with  the  consequent  fractionation  of  the  original  oil, 
are  abundantly  present,  appears  extremely  probable. 

Let  us  examine,  now,  the  conduct  of  the  constituents  of 
petroleum  subjected  to  such  a  fractionation.  The  members 
composing  the  natural  oil  may  be  grouped  under  the  following 
general  heads:  paraffin,  aromatic,  unsaturated  hydrocarbons, 
sulphur,  nitrogen,  and  oxygen  compounds.  The  behavior  of 
the  paraffin  and  unsaturated  hydrocarbons  will  be  considered 
first. 

Dr.  David  T.  Day  early  observed  that  the  unsaturated 
hydrocarbons  are  less  diffusible  than  the  paraffin  hydrocarbons. 
Later,  Gilpin  and  Cram  clearly  demonstrated  that  when  petro- 
leum is  allowed  to  diffuse  through  tubes  packed  with  fuller's 
earth,  the  unsaturated  hydrocarbons  collect  in  the  earth  of 
lower  sections  of  the  tubes,  while  the  paraffins  tend  to  accumu- 
late in  the  lightest  fraction  at  the  top  of  the  tube.  In  the 

1  Z.  angew.  Chem.,  1901,  889. 


II 

present  investigation,  these  results  have  been  fully  confirmed. 
On  pages  50  to  52  are  given  the  bromine  absorption  values, 
and  the  percentages  by  volume  absorbed  by  concentrated 
sulphuric  acid  of  the  various  oils  obtained  from  definite  sec- 
tions of  a  tube.  These  figures  indicate  conclusively  that  the 
amount  of  unsaturated  hydrocarbons  in  the  oils  from  the 
lower  sections  of  the  tube  is  much  greater  than  the  amount  of 
these  hydrocarbons  in  the  lightest  fractions  at  the  top  of  the 
tube.  Furthermore,  the  bromine  absorption  values  for  the 
oils  of  similar  fractions  of  the  first,  second,  and  third  frac- 
tionation,  given  on  page  51,  show  that  in  the  progress  of  the 
fractionation  more  and  more  of  the  unsaturated  hydrocar- 
bons are  removed.  Herr,1  in  Russia,  has  likewise  observed 
that  these  hydrocarbons  are  less  diffusible  than  the  paraffins. 

An  interesting  confirmation  in  nature  of  these  experiments 
has  been  recently  presented  by  Clifford  Richardson  and  K.  G. 
MacKenzie.2  They  found  that  a  colorless  natural  naphtha 
from  the  Province  of  Santa  Clara,  Cuba,  contained  practically 
no  unsaturated  hydrocarbons,  but  was  almost  entirely  a  mix- 
ture of  naphthenes  and  paraffins.  Concentrated  sulphuric 
acid  absorbed  but  0.76  per  cent,  by  volume,  while  fuming 
sulphuric  acid  absorbed  only  1.8  per  cent.  With  the  naphtha 
were  obtained  water  and  an  emulsion  of  water,  oil  and  clay. 
These  investigators  are  of  the  opinion  that  the  naphtha  was 
"undoubtedly  formed  by  the  upward  filtration  of  heavy 
petroleum  through  the  clay  stratum,  similar  to  the  fuller's 
earth  filtrations  of  Gilpin  and  Cram,  and  the  light  naphtha 
in  the  upper  part  of  the  stratum  was  afterwards  partly  libera- 
ted by  saline  waters,  the  oil  remaining  in  the  clay  forming 
with  water  the  emulsion."2 

A  comparison  of  the  proportions  of  unsaturated  hydrocar- 
bons in  Ohio  and  Pennsylvania  oils  shows  that  ttfe  latter  con- 
tains a  much  smaller  percentage  of  these  hydrocarbons.  By 
assuming  that  the  Pennsylvania  oil  diffused  upward  through 
such  porous  media  as  shales  and  limestones  to  its  present 
location  in  the  sandstones,  it  is  possible  to  account  for  the 

1  Petroleum  August,  1909. 

2  Am.  J.  Sci.,  May,  1910. 


12 

smaller  amounts  of  the  olefins  in  it  on  the  basis  of  the  ex- 
perimental work  described  above.  In  its  passage  through 
the  capillary  interstices  of  the  clays,  limestone  and  sandstones, 
a  fractionation,  resulting  in  the  removal  of  the  unsaturated 
hydrocarbons,  probably  occurred.  It  is  reasonable  to  con- 
clude, therefore,  that  the  variation  in  the  content  of  unsatura- 
ted hydrocarbons  between  the  Ohio,  Texas,  and  California 
oils,  on  the  one  hand,  and  the  Pennsylvania  oil  on  the  other, 
can  be  probably  accounted  for  by  assuming  that  the  latter 
was  subjected  to  capillary  diffusion  at  some  time  in  its  career. 
That  the  light-colored  naphthas  occurring  in  various  parts 
of  the  world  were  originally  darker  and  heavier  oils,  and  that 
their  primitive  character  was  changed  by  diffusion  through 
media  possessing  the  power  of  fractionation,  seems  very 
probable. 

The  behavior  of  the  aromatic  hydrocarbons,  in  particular 
benzene,  in  passing  through  fuller's  earth,  constitutes  one  of 
the  subjects  of  this  investigation.  The  results  of  this  study, 
given  in  detail  on  pages  18  to  30,  indicate  clearly  that  ben- 
zene, like  the  olefins,  tends  to  collect  in  the  lower  sections  of 
a  tube  of  fuller's  earth  through  which  the  benzene,  in  solu- 
tion, is  allowed  to  diffuse.  That  the  aromatic  hydrocarbons  in 
the  natural  oil  behave  in  a  similar  manner  has  not  yet  been 
decided.  The  proportion  of  these  hydrocarbons  in  the  Illi- 
nois oil  investigated  was  too  small  to  enable  us  to  determine 
accurately  their  amounts  in  the  various  fractions  obtained 
by  the  capillary  diffusion  of  the  crude  oil.  The  ordinary 
methods,  such  as  nitration  with  a  mixture  of  nitric  acid  and  sul- 
phuric acids,  and  sulphonation,  employed  for  the  quantitative 
determination  of  the  aromatic  hydrocarbons,  could  not  be 
used  in  this  work,  owing  to  the  fact  that  these  reagents  readily 
affect  the  unsaturated  hydrocarbons  as  well.  A  study  of  the 
conduct  of  the  aromatic  hydrocarbons  in  the  natural  oil  con- 
taining large  amounts  of  them  will  be  undertaken  in  the  near 
future.  It  is  probable,  however,  that  the  benzene  and  homol- 
ogous compounds  in  crude  petroleum  behave  like  the  unsatura- 
ted hydrocarbons. 

The  presence  of  larger  amounts  of  aromatic  hydrocarbons 


First  frac- 
tionation. 

Third  frac- 
tionation. 

O.04 

0.003 

0.05 

0.09 

o.  16 

13 

in  the  Ohio  than  in  the  Pennsylvania  petroleum,  and  still 
larger  amounts  in  the  California  and  Texas  oils,  seems  to 
afford  further  evidence  in  favor  of  the  view  that  the  Pennsyl- 
vania oil  has  undergone  much  greater  diffusion,  and  conse- 
quently greater  fractionation,  than  any  of  the  other  oils. 

The  conduct  of  the  sulphur  compounds  in  petroleum  in  the 
process  of  diffusion  is  similar  to  that  of  the  unsaturated  hy- 
drocarbons. On  page  52,  the  percentages  of  sulphur 
present  in  the  oils  from  different  parts  of  the  tube  and  different 
stages  of  fractionation  are  tabulated.  One  series  of  figures 
will  be  given  to  show  the  behavior  of  the  sulphur  compounds: 

Per  cent,  of  sulphur. 

Firsi 
Lot  6. 

Fraction  A 
B 
D 
E 

It  is  clear  from  these  figures  that  the  sulphur  compounds, 
like  the  unsaturated  hydrocarbons,  tend  to  collect  in  the 
lower  sections  of  a  layer  of  fuller's  earth  through  which  petro- 
leum is  allowed  to  diffuse. 

In  1902,  Clifford  Richardson  and  E.  C.  Wallace,1  in  an  in- 
vestigation on  the  occurrence  of  free  sulphur  in  Beaumont 
petroleum,  passed  this  oil  upward  through  the  kaolin  filter 
described  by  Dr.  D.  T.  Day  at  the  Petroleum  Congress  in 
Paris,  in  1900,  and  obtained  a  distinct  fractionation.  The 
percentages  of  sulphur  in  the  crude  oil,  and  the  oils  obtained 
by  this  fractionation  were  determined.  The  results  are  given 
in  the  following  table: 

Per  cent. 
Sp.  gr.  25°/25°.  sulphur. 

Crude  oil  o .  9140  i .  75 

i st  fraction  0.8775  0.70 

2nd  fraction  0.8986  0.91 

3rd  fraction  o .  9038  i .  04 

It  seems  reasonable  to  assume  from  these  results  that  the 
variations  in  the  sulphur  content  between  the  Pennsylvania 

1  J.  Soc.  Chem.  Ind.,  March,  1902. 


and  Ohio  oils  may  be  satisfactorily  explained  by  the  view 
that  the  former  oil,  as  previously  stated,  diffused  from  other 
regions  to  its  present  location,  and  in  its  migration  a  large 
part  of  its  original  content  of  sulphur  was  removed.  Further 
work  upon  this  point  will  be  undertaken  in  this  laboratory. 

No  careful  study  of  the  behavior  of  the  nitrogen  and  oxy- 
gen compounds  in  petroleum  diffusing  through  a  porous 
medium  has  as  yet  been  undertaken.  A  careful  investigation 
of  this  matter  will  be  pursued  in  this  laboratory  later  on. 
It  is  probable  that  such  an  investigation  will  show  that  the 
nitrogen  compounds  conduct  themselves  like  the  sulphur 
and  unsaturated  compounds. 

The  Object  of  this  Investigation. 

The  present  investigation  was  undertaken  for  the  imme- 
diate purpose  of  studying  the  changes  occurring  in  the  crude 
Illinois  oil  when  allowed  to  diffuse  through  fuller's  earth. 
The  more  distant,  but  more  fundamental,  object  was  to  gain 
further  insight  into  the  causes  of  the  variations  between  the 
various  oils  of  this  country. 

EXPERIMENTAL. 
Preliminary  Experiments. 

The  Relative  Amounts  of  Oil  Lost  in  Heated  and  Unheated 
Fuller's  Earth. — Before  the  actual  investigation  of  the  Illi- 
nois oil  was  undertaken,  experiments  were  made  to  deter- 
mine the  relative  amounts  of  oil  lost  in  heated  and  unheated 
fuller's  earth.1  In  the  work  of  Gilpin  and  Cram,  the  earth 
was  always  heated  until  geysers  ceased  to  form,  and  then  al- 
lowed to  cool  for  several  hours.  The  purpose  of  heating  the 
earth  was  to  obtain  larger  yields  of  oil,  but  towards  the  close 
of  their  investigation  it  became  apparent  that  the  amount  of 
oil  lost  in  unheated  fuller's  earth  was  not  as  large  as  they  had 
supposed  it  to  be.  Since  much  time  and  labor  is  consumed 
in  the  process  of  heating  and  then  cooling  the  earth,  it  seemed 
advisable  to  settle  this  point  at  the  outset. 

Apparatus. — The   apparatus   employed   for   this   investiga- 

1  The  fuller's  earth  employed  in  these  investigations  was  generously  supplied  by 
the  Atlantic  Refining  Company  of  Philadelphia. 


V 


tion  was  essentially  the  same  as  that  used  by  Gilpin  and 
Cram.  A,  A,  A,  A  (Fig.  I)  are  tin  reservoirs  made  to  hold 
somewhat  more  than  a  liter.  The  tin  tubes  B,  B,  B,  B,  5.5 
feet  in  length,  and  1.25  inches  in  diameter,  rest  upon  narrow 
tin  supports  placed  upon  the  bottom  of  the  reservoirs,  and 
are  connected  with  the  branched  glass  tube  F  by  suction  tub- 
ing fitted  with  pinchcocks  at  E,  E,  E,  E.  The  tube  F  is  con- 
nected with  the  large  tank  C,  which  serves  to  maintain  fairly 
constant  pressures;  C  is  in  turn  joined  by  the  glass  tube  D 
to  a  manometer,  and  the  latter  connected  with  the  Chapman 
pump.  Any  number  of  these  tubes  may  be  set  up  in  series 
under  the  same  diminished  pressure. 
F 


After  the  tubes  are  closed  at  their  lower  ends  with  grooved 
corks  covered  with  muslin  to  prevent  the  earth  from  sifting 
out,  they  are  packed  to  the  desired  firmness  with  the  fuller's 
earth.  Bach  tube  is  then  placed  in  its  own  reservoir,  con- 
taining the  oil  to  be  fractionated.  When  they  are  connected 
to  the  branched  tube  F,  the  pressure  in  the  system  of  tubes 
is  reduced  by  the  suction  pump.  The  oil  rises  at  first  rapidly, 
then  its  diffusion  gradually  diminishes  in  power.  When  the 
reservoirs  are  almost  exhausted,  the  tubes  are  disconnected 


i6 

and  clamped,  with  the  bottom  ends  up,  above  shorter  tubes 
of  the  same  diameter,  into  which  the  oil-laden  earth  is  allowed 
to  slide.  These  shorter  tubes  are  made  of  two  curved  pieces, 
joined  at  the  bottom  by  a  cap,  and  held  together  at  the  top 
by  a  ring.  The  cylinders  are  opened  by  slipping  off  the  ring 
and  cap  and  removing  one  of  the  curved  pieces,  and  the  earth 
divided  into  the  desired  sections.  When  water  is  added  in 
portions  to  the  earth  and  the  two  mixed  thoroughly,  the  oil 
is  displaced  and  is  drawn  off  in  separate  portions. 

Six  tubes  packed  with  heated  fuller's  earth  were  set  up  al- 
ternately with  six  tubes  filled  with  the  unheated  earth.  Each 
tube  was  placed  in  its  own  reservoir  containing  950  cc.  of 
crude  oil.  The  oil  was  allowed  to  diffuse  upward  through 
the  tubes  under  diminished  pressure.  Sixteen  hours  elapsed 
before  the  oil  in  the  reservoirs  was  exhausted.  Since  the 
tubes  did  not  rest  directly  upon  the  bottom  of  the  reservoirs, 
a  small  amount  of  oil  remained,  the  volume  of  which  was 
subtracted  from  the  volume  originally  supplied.  The  earth 
from  each  tube  was  shaken  into  a  bucket,  and  the  oil  recov- 
ered by  displacement  with  water,  as  described  above.  The 
results  of  these  experiments  are  given  in  the  following  table : 

Table  I.— Heated  Fuller's  Earth. 


Weight  of 
fuller's  earth. 

Oil  absorbed 
by  earth. 

Oil 
recovered. 

Oil  lost. 

Per  cent, 
oil  lost 

Tubes. 

Grains. 

cc. 

cc. 

cc. 

cc. 

I 

1005 

850 

450 

390 

46 

3 

1000 

792 

460 

332 

41 

5 

1035 

850 

500 

350 

41 

7 

1070 

865 

450 

4*5 

48 

9 

1035 

813 

430 

383 

47 

ii 

1045 

885 

530 

355 

4i 

Total,     5055         2830         2225  44 

Unheated  Fuller's  Earth. 


2 

1075 

917 

585 

332 

36 

4 

1095 

853 

562 

291 

34 

6 

1065 

840 

500 

340 

42 

8 

1045 

814 

435 

379 

46 

10 

1035 

873 

5io 

363 

4i 

12 

1055 

850 

485 

365 

4i 

Total,     5147        3077         2070  40 


17 

The  petroleum  employed  in  the  above  experiments  was  a 
dark,  green  oil  from  Venango  County,  Pennsylvania,  possess- 
ing a  specific  gravity  of  0.810. 

Since  the  Illinois  oil,  which  was  used  in  the  fractionation 
proper,  described  later,  differs  materially  from  the  Pennsyl- 
vania petroleum,  further  experiments  were  undertaken  to 
determine  the  relative  amounts  of  this  oil  retained  by  heated 
and  unheated  earth. 

Ten  tubes,  five  of  which  were  packed  as  uniformly  as  possible 
with  fuller's  earth  that  had  been  heated  until  geysers  ceased 
to  form,  and  the  other  five  with  unheated  earth,  were  placed 
in  reservoirs,  each  containing  950  cc.  of  Illinois  oil,  specific 
gravity  0.8375.  When  the  oil  was  entirely  absorbed,  the 
tubes  were  taken  down  and  the  oil-laden  earth  shaken  into 
two  breakable  cylinders  and  divided  into  the  following  sec- 
tions: A  constitutes  the  section,  10  cm.  in  length,  measured 
downward  from  the  level  to  which  the  oil  had  ascended;  B, 
the  next  15  cm. ;  C,  20  cm. ;  D,  30  cm. ;  E,  35  cm. ;  the  remainder 
of  the  earth  to  the  bottom  of  the  tube,  designated  as  F,  was 
entirely  discarded. 

The  earth  was  then  treated  with  separate  portions  of  water. 
The  oils  displaced  by  the  successive  additions  of  water  were 
collected  separately  and  are  designated  in  the  table  below 
as  Aj,  A2,  Blt  B2,  and  so  on;  A^  is  the  oil  first  displaced,  A2  the 
oil  next  expelled  by  further  additions  of  water.  The  volumes 
and  specific  gravities  of  the  recovered  oils  were  determined. 
The  results  are  given  in  the  following  table: 

Table  II. 

Heated  fuller's  earth.  Unheated  fuller's  earth. 


Frac. 

Spec.  grav. 

Vol.,  cc. 

Spec.  grav. 

Vol.,  cc. 

A, 

0.8287 

100 

0.8320 

72 

A, 

.... 

0.8352 

22 

B, 

0.8390 

157 

o  .  8405 

184 

B2 

0.8485 

35 

0.8451 

124 

Ci 

0.8441 

280 

0.8443 

270 

c, 

0.8507 

67 

o  -  8495 

H7 

*>, 

o  .  8450 

393 

0.8483 

368 

D, 

o  .  8490 

132 

0.8517 

210 

Et 

0-8537 

339 

0.8500 

360 

E, 

0.8564 

174 

0.8569 

185 

1701  1942 


i8 

These  results  indicate  that  unheated  fuller's  earth  retains 
no  more  oil  than  the  heated  earth.  Although,  in  these  ex- 
periments, the  percentage  of  oil  lost  in  the  unheated  is  smaller 
than  that  lost  in  the  heated  earth,  Gilpin  and  Cram,  employ- 
ing heated  earth,  recovered,  in  one  test,  5,951  cc.  from  9,070 
cc.,  and,  in  another,  5,415  cc.  from  8,915  cc.,  the  amount  of 
oil  lost  in  the  earth  in  the  first  test  corresponding  to  34  per 
cent.,  in  the  second  to  39  per  cent.  It  is  clear,  therefore,  that 
there  is  no  sufficient,  if  any,  compensation  for  the  time  and 
labor  spent  in  heating  the  earth.  In  the  investigations  that 
followed,  therefore,  the  unheated  fuller's  earth  was  always 
used. 

The  Diffusion  of  Benzene  in  Solution  through  Fuller's  Earth. — 
In  order  to  deal  more  intelligently  with  the  fractionation  of 
the  crude  Illinois  petroleum,  it  seemed  advisable  to  study 
the  behavior  of  the  individual  aromatic  hydrocarbons,  espe- 
cially benzene,  both  alone  and  mixed  with  paraffin  hydrocar- 
bons, when  allowed  to  diffuse  upward  through  fuller's  earth. 
Gilpin  and  Cram  established  the  fact  that  the  paraffin  hydro- 
carbons tend  to  collect  in  the  lightest  fractions  at  the  top  of 
the  tube.  Their  method  consisted  in  distilling  by  heat  six 
samples  of  oils  of  different  specific  gravities,  each  300  cc. 
in  volume,  and  collecting  ten  fractions  between  definite  inter- 
vals. Five  of  these  samples  consisted  of  oil  partly  fractiona- 
ted by  fuller's  earth,  and  the  other  of  the  crude  oil.  The 
specific  gravity  and  \iscosity  of  each  fraction  were  deter- 
mined; then  to  30  cc.,  or  to  all  there  was  where  the  amount 
was  less  than  30  cc.,  an  equal  volume  of  concentrated  sul- 
phuric acid  (specific  gravity  1.84)  was  added,  and  the  two 
shaken  in  a  machine  for  half  an  hour  or  longer.  The  volume 
of  the  oil  unaffected  by  the  acid  was  measured,  and,  by  sub- 
traction, the  volume  of  oil  absorbed  was  calculated.  This 
latter  volume  represents  only  approximately  the  percentage 
of  unsaturated  hydrocarbons  present  in  the  oil,  because  sul- 
phuric acid  of  this  strength  readily  dissolves  benzene  when 
the  two  are  thoroughly  shaken. 

In  this  investigation  various  solutions  of  benzene  and  a 
refined  paraffin  oil,  boiling  between  160°  and  240°,  and  only 


19 

slightly  attacked  by  sulphuric  acid,  were  made  up  and  allowed 
to  rise  in  tubes  packed  with  unheated  fuller's  earth.  The 
pressure  in  the  system  was  reduced  very  little,  because  the 
liquid,  under  a  greatly  diminished  pressure,  rose  too  rapidly. 
About  24  hours  elapsed  before  the  oil  in  the  reservoirs  was 
exhausted. 

The  earth  in  each  tube  was  shaken  out  and  divided  into  six 
sections.  Beginning  at  the  uppermost  point  to  which  the 
oil  had  ascended,  grade  A  consisted  of  the  first  8  cm. ;  grade  B 
of  the  next  8  cm. ;  grade  C  of  18  cm. ;  grade  D  of  30  cm. ;  grade 
E  of  35  cm. ;  and,  finally,  grade  F  of  the  remainder  of  the  earth, 
depending  on  the  height  to  which  the  oil  had  ascended.  This 
division  is  the  same  as  that  used  by  Gilpin  and  Cram.  The 
oil  in  the  earth  was  displaced  by  water  and  drawn  off. 

The  specific  gravity  of  each  fraction  was  determined  by 
means  of  the  Mohr-Westphal  balance  at  exactly  20°.  The 
fourth  decimal  is  not  to  be  considered  as  strictly  accurate, 
but  gives  a  closer  approximation  to  the  truth  than  if  it  were 
entirely  discarded. 

The  viscosity  was  determined  by  means  of  the  viscosom- 
eter  described  by  Ostwald  and  Luther  and  modified  by  Jones 
and  Veazey.1  The  time  taken  for  measured  volumes  of  the 
oils  to  drain  from  the  small  bulb,  whose  capacity  was  4.5  cc.,  was 
compared  with  the  time  required  for  a  similar  amount  of  water 
to  run  through.  These  values  were  substituted  in  the  equation 

TS 

"y°  T0S0' 

where  y0  =  coefficient  of  viscosity  of  water.     For  this,  0.01002, 
the  value  obtained  by  Thorpe  and  Rodger,2  was  used. 
t  =  time  of  flow  of  liquid  under  examination. 
S  =  specific  gravity,  measured  at  20°,  of  liquid  under  ex- 
amination. 

TQ  =  time  of  flow  of  water. 

S0  =  specific    gravity    of    water.     Since    the  balance    was 
calibrated  for  water,  at  20°,  the  value  for  S  is  unity. 
y  =  coefficient  of  viscosity  of  oil  under  examination. 

1  Z.  physik.  Chem.,  61,  351. 

2  Phil.  Trans.,  A,  185,  397  (1894). 


20 

The  amount  of  benzene  present  in  each  fraction  was  deter- 
mined by  shaking  the  oil  with  an  excess  of  ordinary  concen- 
trated sulphuric  acid  (specific  gravity  1.84)  for  periods  of 
time  varying  from  30  to  60  minutes,  until  there  was  no  further 
diminution  in  the  volume  of  the  oil. 

The  following  experiments  demonstrate  the  power  of  this 
acid  to  dissolve  benzene,  forming  benzenesulphonic  acid: 

(1)  Twenty-five    cc.    of    benzene    were    shaken    vigorously 
in  a  machine  with  25  cc.  of  concentrated  sulphuric  acid  (specific 
gravity  1.84)  for  30  minutes.     Amount  of  benzene  dissolved, 
7  cc.,  or  28  per  cent. 

(2)  Twenty-five  cc.  were  shaken  for  30  minutes  with  50  cc. 
of  acid.     Amount  of  benzene  dissolved,  18  cc.,  or  72  per  cent. 

(3)  Twenty-five  cc.  were  shaken  for  30  minutes  with  75  cc. 
of  acid.     Amount  of  benzene  dissolved,  25  cc.,  or  100  per  cent. 

The  reagents  usually  employed  for  removing  benzene  are 
a  mixture  of  fuming  nitric  and  concentrated  sulphuric  acids. 
The  work  of  Worstall,1  Francis  and  Young,2  and  others,  shows 
that  such  a  mixture  readily  attacks  the  paraffin  hydrocarbons, 
especially  at  higher  temperatures,  forming  nitro  derivatives, 
and  also  oxidizing  them  to  a  considerable  extent.  Further- 
more, in  working  with  this  mixture  the  oil  must  be  kept  at  a 
low  temperature  to  prevent  a  violent  reaction  which  results 
usually  in  the  decomposition  of  the  oil.  In  this  work,  there- 
fore, in  order  to  avoid  the  danger  of  attacking  the  paraffin 
hydrocarbons,  and  or  the  sake  of  convenience,  concentrated 
sulphuric  acid  was  used. 

It  seems  advisable,  at  this  point,  to  call  attention  to  the 
fact  that  the  power  of  ordinary  concentrated  sulphuric  acid 
to  remove  benzene  and  homologous  hydrocarbons  has  been 
generally  overlooked.  In  order  to  determine  the  percent- 
ages of  these  hydrocarbons,  it  is  customary  to  shake  the  oils  to 
be  analyzed  with  concentrated  sulphuric  acid,  and  then  to 
nitrate  the  unaffected  oil.  It  is  assumed  that  the  acid  re- 
moves such  substances  as  the  unsaturated  hydrocarbons, 
and  does  not  attack  the  aromatic  hydrocarbons.  Thus,  P. 

1  Amer.  Chem.  J.,  20,  202;  21,  210. 

2  J.  Chem.  Soc..  1898,  928. 


21 

Poni,1  in  determining  the  presence  and  percentage  of  aromatic 
hydrocarbons  in  Roumanian  petroleum,  collected  fractions 
between  35°  and  70°,  distilled  under  diminished  pressure. 
These  were  purified  by  shaking  with  sulphuric  acid,  and  each 
nitrated  with  a  mixture  of  i  part  of  nitric  acid  (specific  grav- 
ity 1.52)  and  2  parts  sulphuric  acid  (specific  gravity  1.8). 
The  recovered  oils  were  assumed  to  be  paraffins  and  naphthenes, 
while  the  proportion  of  benzene  and  unsaturated  hydrocar- 
bons was  calculated  from  the  nitro  products  obtained.  It  is 
obvious  from  the  results  obtained  in  the  present  work  that 
some  of  the  benzene  was  removed  in  the  process  of  purifying 
the  fractions.  The  amount  dissolved  would  depend  upon 
the  vigor  of  the  shaking  and  its  duration,  as  well  as  on  the 
strength  of  the  sulphuric  acid.  It  is  highly  probable,  there- 
fore, that  his  percentage  of  benzene  is  too  low. 

In  the  study  of  the  mixture  of  benzene  and  paraffin  hydro- 
carbons, twenty-five  cc.  of  each  fraction,  or  the  whole  frac- 
tion when  it  was  less  than  25  cc.,  were  shaken  vigorously 
with  three  times  their  volume  of  concentrated  sulphuric  acid 
for  30  minutes.  The  amount  unabsorbed  was  measured  over 
the  acid  in  a  burette,  after  sufficient  time  was  allowed  for 
most  of  the  oil  that  was  mechanically  held  in  suspension  to 
rise.  The  oil  was  then  reshaken  with  a  little  more  acid  15 
minutes  longer,  and  the  volume  again  read.  In  cases  where 
the  benzene  was  present  only  in  small  quantities  one  shaking 
was  sufficient,  in  other  cases  it  was  repeated  a  second  time. 

The  paraffin  oil  employed,  specific  gravity  0.797,  was  shaken 
several  times  with  fresh  portions  of  concentrated  sulphuric 
acid  until  the  acid  was  no  longer  colored,  and  only  a  slight 
diminution  in  volume  occurred  when  a  small  sample  of  the 
oil  was  thoroughly  shaken  in  a  machine  for  some  time  with 
the  acid.  The  oil  was  then  washed  with  water  and  sodium 
hydroxide  and  dried  over  calcium  chloride.  The  specific 
gravity  decreased  to  0.792. 

When  this  oil  was  mixed  with  benzene  in  various  propor- 
tions, and  allowed  to  diffuse  upward  through  fuller's  earth, 
the  following  results,  arranged  in  series,  were  obtained: 

1  Ann.  Sci.  Univ.  Jassy,  1907,  192-202  (abstracted  in  J.  Chem.  Soc.,  92,  II,  883 
(1907)). 


Volume  of 
oil,  cc. 

Specific 
gravity. 

Viscosity. 

II 

0.789 

.... 

I? 
60 

0.792 
0.7912 

0.0154 

100 

0.7915 

0.0140 

150 

0.7913 

0.0134 

139 

0.7915 

0:0134 

22 

Table  III. 

Series  i. — Oil  alone.     Specific  gravity  0.792.     Level  of  oil, 

28  cm. 

Per  cent. 
Grade.  oil,  cc.          gravity.  Viscosity.          benzene.2 

A 
B 
C 
D 
E 
F 

4771 
Orig.  vol.,     778 

Series  2. — 90  per  cent,  oil  (o.792)-io  per  cent,  benzene  (0.8775). 
Specific  gravity,  0.7983.     Level  of  oil,  22  cm. 

Volume  of         Specific  Per  cent. 

Grade.  oil,  cc.  gravity.  Viscosity.          benzene. 

A  ii  0.787  ....  10. o 

B  16  0.7923           13.3 

C  56  0.7935  0.0131  ii. 6 

D  109  0.7943  0.0123  14.8 

E  145  0.7957  0.0120  14.4 

F  245  0.7955  0.0116  14.8 

582 
Orig.  vol.,     872 

The  results  that  are  tabulated  in  the  various  series  are  ex- 
pressed diagrammatically  in  the  following  curves.  The 
ordinates  represent  the  different  grades  of  oil,  and  the  ab- 
scissas, the  percentages  of  benzene  and  the  specific  gravities. 

The  final  curve  represents  in  toto  the  results  of  the  experi- 
mental work  upon  the  diffusion  of  benzene  in  solution  through 
fuller's  earth.  The  ordinates  of  this  curve  represent  the  per- 
centages of  benzene,  and  the  abscissas,  the  various  mixtures 
of  benzene  and  oil  that  were  allowed  to  diffuse  through  the 
earth. 

1  The  original  volumes  of  solution  vary  with  each  series,  owing  to  the  fact  that 
more  or  less  always  remained  behind  in  the  reservoir  below  the  level  of  the  tin  sup- 
port.    In  Series  1,  2,  3,  and  4,  950  cc.  were  supplied  to  each  reservoir;  in  the  rest  of  the 
series,  each  reservoir  contained  originally  1 ,000  cc. 

2  In  this  series  the  percentages  of  benzene  are  not  given,  because  the  paraffin  oil 
alone  was  used. 


0  IO  20 

Per  cent.  Benzene. 


OO         O.JQOO          O.800O 

Specific  Gravity. 


Fig.  II.       Series  2. 


Series  3. — 80  per  cent,  oil  (o.792)-2o  per  cent,  benzene  (0.8775) 
Specific  gravity,  0.806.     I^evel  of  oil,  25  cm. 


Grade. 

A 
B 
C 
D 
E 
F 


Orig.  vol., 


Volume  of 

Specific 

Per  cent. 

oil,  cc. 

gravity. 

Viscosity. 

benzene. 

25 

0.7948 

0.0147 

15-3 

35 

0.7981 

0.0130 

16.0 

78 

0.8017 

O.OII7 

22.4 

126 

0.80O5 

0.0105 

21.6 

166 

0.801 

0.0107 

22.4 

146 

0.798 

O.OIIO 

20.8 

576 

,     892 

Series  4. — 75  per  cent,  oil  (o.792)-25  per  cent,  benzene  (0.8775), 
Specific  gravity,  0.810.     Level  of  oil,  33  cm. 


Grade. 

Volume  of 
oil,  cc. 

Specific 
gravity. 

Viscosity.1 

Per  cent, 
benzene. 

A 

16 

0.800 

.... 

22.0 

B 

35 

0.803 

0.0129 

23-3 

C 

74 

0.8077 

O.OI26 

24.0 

D 

128 

0.805 

O.OII4 

24.0 

E 

152 

0.8068 

O.OIO2 

26.O 

F 

120 

0.8065 

0.0105 

28.0 

525 

Orig.  vol., 

655 

i. 


O       IO     2O      30  O.JQOO  0.8OOO  O.SlOO 

Per  cent.  Benzene.  Specific  Gravity. 

Fig.  III.     Series  a. 


lo         20         30  0.7900  0.8000  0.8100 
Per  cent.  Benzene.     Specific  Gravity. 
Fig.  IV.     Series  4. 


1  The  viscosities  of  Grades  A  and  B  in  a  few  of  the  tables  are  not  given,  because, 
in  these  series,  which  were  the  first  to  be  made,  the  decision  to  determine  the  viscosi- 
ties was  reached  only  after  the  fractions  had  been  treated  with  acid.  Since  A  and  B 
were  small,  all  the  oil  was  used  up  in  this  treatment. 


Series  5. — 75  per  cent,  oil  (0.794)  *-2  5  Per  cent-  benzene 
(0.8775).     Specific  gravity,  0.8115.     Level  of  oil,  24  cm. 


Volume  of 

Specific 

Per  cent. 

Grade.                        oil,  cc. 

gravity.             Viscosity. 

benzene. 

A                        25 

0.7942            0.0123 

14.0 

B                       28 

0.8048            0.0104 

21  .2 

C                       70 

O.8lO5            O.OO94 

31.2 

D                     140 

O.SlOO            0.0094 

27.6 

E                     172 

O.SlOO            0.0094 

32.0 

F                      144 

0.8093            0.0095 

27.6 

579 

Orig.  vol.,     875 

Series  6.  —  75  per  cent,  oil  (o.792)-25  per  cent,  benzene  (0.8775). 

Specific  gravity,  o 

8083.     Level  of  oil,  27 

cm. 

Volume  of 

Specific                                       Per  cent. 

Grade.                         oil,  cc. 

gravity.             Viscosity. 

benzene. 

A                                 22 

0-7995         0.0106 

17-5 

B                       32 

0.8055         0.0099 

24.4 

C                       82 

0.8052         o.oioo 

24.0 

D                     155 

0.8085        0.0093 

28.8 

E                     190 

0.8085         0.0093 

31.2 

F                       93 

o  .  8063         o  .  0096 

28.8 

574 

Orig.  vo 

1-,     923 

\ 

|  ] 

} 

10     20     30  0.7QOO  0.8200  O 

O.8000  O.SlOO 

Per  cent.  Benzene.         Specific  Gravity. 
Fig.  V.    Series  5. 


IO     2O     30  O.JQOO  0.820O 

0.80OO  O.SlOO 

Per  cent.  Benzene.       Specific  Gravity. 
Fig.  VI.    Series  6. 


1  In  Series  5,  8,  9  and  10  the  specific  gravity  of  the  refined  oil  is  0.794.  Since 
the  quantity  of  oil  of  specific  gravity  0.792  was  not  sufficient  for  all  the  series,  a  sec- 
ond quantity  was  prepared  which  had  the  specific  gravity  0.794.  This  oil  was  used 
in  the  above-mentioned  series. 


26 


Series  7. — 59.5  per  cent,  oil   (o.792)~4o.5  per  cent,  benzene 
(0.8775).     Specific  gravity,  0.8223.     Level  of  oil,  9  cm. 


Grade. 

Volume  of       Specific 
oil,  cc.         gravity. 

Viscosity. 

Per  cent, 
benzerte. 

A 

91 

.... 

.... 

B 

15 

o  .  8069 

14.0 

C 

48 

0.816 

0.0103 

22.4 

D 

96 

0.8182 

o  .  0086 

31.2 

E 

160 

0.820 

0.0082 

31-6 

F 

255 

0.8185 

o  .  0083 

29.6 

583 

Orig.  vol.,     922 

Series  8.  —  50  per  cent,  oil 

(o.794)-5o 

per  cent,  benzene  (0.8775). 

Specific  gravity, 

0.8295.     Level  of  oil,  17  cm. 

Volume  of 

Specific 

Per  cent. 

Grade. 

oil,  cc. 

gravity. 

Viscosity. 

benzene. 

A 

22 

0.8l22 

.... 

24-5 

B 

32 

0.819 

28.4 

C 

78 

0.8287 

O.0077 

44.8 

D 

III 

0.8275 

0.0077 

47  -6 

E 

155 

0.827 

0.0077 

39-2 

F 

I92 

0.8256 

0.0079 

36.4 

590 

Orig.  vol.,     960 

A 

• 

V 

\ 

B 

\ 

\ 

x^ 

\ 

C 

\ 

^ 

{ 

\ 

) 

D 

| 

\ 

) 

E 

1 

F 

30  0.7900   0.8100     o 
0.8000    0.8200 


30 


40  0.7000          0.8100        0.8300 
0.8000.         0.8200  &"™" 


Per  cent.  Benzene.       Specific  Gravity.  Per  cent.  Benzene.        Specific  Gravity. 
Fig.  VII.       Series  7.  Fig.  VIII.       Series  8. 

1  In  Series  7  the  volume  of  Grade  A  recovered  was  so  small  that  no  measure- 
ments could  be  made. 


Series  9. — 50  per  cent,  oil  (o.  794^50  per  cent,  benzene  (0.8775), 
Specific  gravity,  0.8315.     Level  of  oil,  18  cm. 


Grade. 

Volume  of 
oil.  cc. 

Specific 
gravity. 

Viscosity. 

Per  cent, 
benzene. 

A 

18 

0.816 

O.OO9I 

26.0 

B 

24 

0.8210 

o  .  0085 

34-5 

C 

76 

0.8275 

0.0078 

47.6 

D 

136 

0.8283 

0.0077 

50.0 

E 

174 

0.8293 

O.OO76 

49-2 

F 

144 

0.8277 

0.0078 

40.0 

572 

Orig.  vol.,     923 

Series    10.  —  50 

per   cent. 

oil    (o.794)-5o   per 

cent,   benzene 

(0.8775).     Specific  gravity,  0.8295.     Level  of 

oil,  1  6  cm. 

Volume  of 

Specific 

Per  cent. 

Grade. 

oil,  cc. 

gravity. 

Viscosity. 

benzene. 

A 

31 

0.8135            0.0097 

31.6 

B 

45 

0.8251 

o  .  008  i 

43-6 

C 

85 

0.8290            0.0076 

46.4 

D 

140 

0.8280            0.0077 

47.6 

E 

175 

0.8285            0.0076 

49.6 

F 

137 

0.8272            O.O076 

50.0 

613 

Orig.  ^ 

/ 

rol.,      972 

\ 

} 

\ 

1) 

10     20       30     40     0.7900         0.8100         0.8300  o     10     20      30       40  0.7900     0.8100       0.8300 

0.8000       0.8200  0.8000       0.8200 

Per  cent.  Benzene.  Specific  Gravity.  Per  cent.  Benzene.  Specific  Gravity. 

Fig.  IX.       Series  9.  Fig.  X.  Series  10. 


28 


Series  u. — 75  per  cent,  crude  oil  (o.8io)-25  per  cent,  benzene 
(0.8775).     Specific  gravity,  0.8312.     Level  of  oil,  18  cm. 


Grade. 

A 

B 
C 
D 
E 
F 


Volume  of 

Specific 

oil,  cc. 

gravity. 

Viscosity. 

12 

0.8255 

0.0445 

22 

0.8268 

0.0423 

52 

0.8280 

o  .  0300 

76 

0.8290 

0.0298 

140 

o  .  8300 

0.0263 

186 

O.8320 

0.0276 

Per  cent. 
benzene.1 


Orig.  vol., 


488 
890 


Series  12. — Benzene  alone  (0.8775).     Level  of  oil,  33  cm. 


Grade. 

A 
B 
C 
D 
E 
F 


Volume  of 

Specific 

oil,  cc 

gravity. 

16 

0.8765 

15 

0.877 

68 

0.878 

128 

0.8778 

157 

0.8775 

89 

0.8771 

Viscosity. 


O . OO66 
O . 0066 
O . OO66 
O . 0066 


Per  cent, 
benzene. 


473 


Orig.  vol., 


An  examination  of  these  figures  shows  conclusively  that 
benzene  tends  to  collect  in  the  lower  portions  of  the  tube. 
The  specific  gravities  and  viscosities  confirm  the  results  ob- 
tained by  determining  the  percentages  of  benzene  present  by 
removing  the  benzene  with  concentrated  sulphuric  acid.  The 
specific  gravities  of  Grades  F  to  C  run  very  close  together, 
and  are  all  much  greater  than  those  of  Grades  A  and  B.  Since 
benzene  possesses  a  high  specific  gravity  (in  this  work  the 
specimen  had  a  specific  gravity  of  0.8775),  tne  larger  value 
for  the  lower  grades  indicates  the  presence  of  larger  amounts 
of  benzene.  The  specific  gravity  of  the  paraffin  oil  was  only 
0.792,  showing  that  the  higher  specific  gravities  were  due  to 
larger  percentages  of  benzene.  Further,  since  the  viscosity 

1  The  percentages  of  benzene  in  Series  11,  in  which  crude  oil  was  employed,  are 
not  recorded,  because,  owing  to  the  formation  of  heavy  black  emulsions,  the  loss  in 
volume  could  not  be  determined  with  any  degree  of  accuracy. 


3° 


10%  Benzene 
QO%  Oil 


20%  Benzene 
80%  Oil 


Mixtures  Fractionated. 
Fig.  XI. 


25%  Benzene 
75%  Oil 


50%  Benzene 
50%  Oil 


30 

of  the  benzene  used  was  0.0066,  and  that  of  the  paraffin  oil 
about  0.0150,  the  viscosities  of  those  fractions  containing 
higher  percentages  of  benzene,  we  should  expect,  ought  to  be 
much  smaller  than  those  containing  less  benzene.  The  re- 
sults show  that  the  viscosities  of  the  Grades  F  to  C  are  much 
smaller  than  those  of  A  and  B. 

It  will  be  observed  that  the  maximum  in  specific  gravity 
is  reached,  not  at  F,  as  might  be  expected  in  the  f  ractionation 
of  the  crude  oil,  but  between  C  and  D.  Between  B  and  C 
there  is  a  marked  decrease.  This  sudden  break  is  found  also 
in  the  viscosities,  and  in  the  percentages  of  benzene.  While 
the  sharp  breaks  in  the  curves  represent  the  marked  change 
in  the  proportion  of  benzene  and  the  height  to  which  it  rises 
in  the  tube,  no  satisfactory  explanation  has  yet  been  ob- 
tained as  to  why  it  should  occur  at  these  points.  This  action 
will  be  studied  more  carefully  later. 

In  order  to  determine  the  degree  of  exactness  of  the  per- 
centages of  benzene  obtained,  known  amounts  of  benzene 
were  added  to  the  oil  until  the  specific  gravity  corresponded 
closely  to  that  obtained  by  f  ractionation.  The  amount  of 
benzene  thus  added  and  the  amount  actually  removed  by  the 
acid  agree  very  closely,  as  the  following  results  show: 

Benzene  found  in  the 


Benzene  in  25  cc. 

grades  of  Series  8. 

of  mixture. 

Specific  gravity. 

cc. 

Specific  gravity. 

7 

•3 

0. 

8143 

Grade  A 

7 

9 

0. 

8135 

9 

•4 

0. 

8213 

"   '  B 

10 

•9 

O 

8251 

ii 

.1 

O. 

8274 

M          77* 

12 

•5 

0 

,8272 

ii 

•3 

0. 

8287 

"     E 

12 

•4 

0 

.8287 

ii 

•9 

o. 

8293 

"     C 

II 

.6 

O 

.8290 

The  variations  in  the  specific  gravities  of  the  mixtures  and 
those  of  the  grade  A-F  are  due  to  the  fact  that  in  the  latter 
series  some  f  ractionation  had  taken  place,  and  therefore  the 
paraffin  oils  mixed  with  the  benzene  were  not  identical  with 
those  mixed  with  the  benzene  in  the  series  of  prepared  mix- 
tures, as  the  paraffin  oil  used  was  not  an  individual  substance 
but  a  mixture. 


The  Fractionation  of  Crude  Petroleum. 

The  petroleum  employed  for  the  fractionation  was  an  oil 
obtained  from  the  E.  E.  Newlin  farm,  2.5  miles  west  of  Robin- 
son, Crawford  County,  Illinois.  The  specific  gravity  of  the 
oil  was  0.8375  at  20°;  its  color  was  dark  brown. 

The  fractionation  of  the  oil  was  effected  by  upward  diffusion 
through  tubes  packed  with  fuller's  earth.  In  order  to  shorten 
the  time  required  for  the  oil  to  diffuse  by  capillarity  to  the 
upper  parts  of  the  tube,  the  fine  interstices  and  pores  of  the 
earth  were  evacuated  by  applying  diminished  pressure  at  the 
top  of  the  tube.  By  this  aid,  the  time  required  for  the  oil 
to  reach  the  top  of  a  tube  was  reduced  from  several  weeks 
to  one  or  two  days. 

The  apparatus  employed  is  the  same  as  that  described  on 
page  14. 

The  tin  tubes  were  packed  as  uniformly  as  possible  by  in- 
troducing definite  amounts  of  earth,  and  ramming  solidly 
with  rods  tipped  with  rubber  stoppers.  The  degree  of  com- 
pactness depended  upon  the  kind  of  oil  to  be  used.  For  the 
crude  oil,  about  one  and  one-half  feet  of  the  tube  was  filled 
at  a  time,  and  the  earth  packed  as  firmly  as  possible;  for  the 
lighter  oils,  one  foot  of  the  tube  was  filled  at  a  time;  for  the 
oils  heavier  than  the  crude,  between  two  and  three  feet  of  the 
tube  were  filled  at  one  time. 

The  tubes  were  then  placed  individually  in  reservoirs  con- 
taining 950  cc.  of  the  crude  oil,  after  which  diminished  pres- 
sure was  applied  at  the  top  of  the  tubes.  The  oil  rose  rapidly 
at  first,  then  diffused  more  and  more  slowly  as  the  tops  of  the 
tubes  were  approached.  When  the  oil  in  the  reservoirs  was 
completely  exhausted,  the  tubes  were  disconnected  from  the 
blanched  glass  tube  F  (see  Fig.  I)  and  the  oil-laden  earth 
shaken  into  two  breakable  cylinders.  For  the  various  frac- 
tions, the  following  divisions  of  the  earth  were  made:  Frac- 
tion A  constituted  the  first  10  cm.,  measured  downward  from 
the  level  to  which  the  oil  had  ascended;  fraction  B,  the  next 
15  cm.;  C,  20  cm.;  D,  30  cm.;  E,  35  cm.,  and  F,  the  remainder 
to  the  bottom  of  the  tube.  In  the  first  fractionation  up  to 


32 

Lot  28,  fraction  F  was  dicarded;  from  Lot  28  to  the  end  of 
the  first  fractionation,  E  and  F  were  collected  together. 

After  thus  dividing  the  earth,  the  various  portions  were 
placed  in  separate  receptacles  and  treated  with  water.  After 
each  addition  of  water  the  two  were  thoroughly  mixed.  The 
earth,  when  the  oil  first  appears,  is  granular;  as  more  water 
is  added,  liberating  more  oil,  the  earth  becomes  muddy,  and 
when  as  much  oil  as  possible  has  been  expelled  by  the  water, 
the  earth  has  the  consistency  of  glue. 

The  portions  of  oil  liberated  by  successive  additions  of 
water  were  collected  separately.  As  Gilpin  and  Cram1  pointed 
out,  the  oil  that  is  first  expelled,  if  not  very  small  in  volume 
as  compared  with  the  oils  succeeding,  possesses  a  lower  specific 
gravity  than  the  oil  liberated  by  further  additions  of  water; 
the  latter,  in  turn,  is  lighter  than  the  next  succeeding  oil.  The 
oil  that  is  liberated  last,  therefore,  possesses  a  higher  specific 
gravity  than  any  of  the  oils  preceding  it.  Sometimes,  how- 
ever, the  specific  gravity  remains  constant  after  the  second 
or  third  extraction.  This  fractionation,  by  means  of  water, 
was  combined  with  the  fractionation  effected  by  the  fuller's 
earth.  In  the  tables  that  follow,  Al  is  the  oil  first  liberated, 
A 2  the  oil  next  liberated;  in  the  lower  fractions,  i.  e.,  C,  D,  E, 
three  and  sometimes  four  extractions  were  made  before  all 
the  oil  that  could  possibly  be  liberated  by  water  was  recov- 
ered. 

The  specific  gravity  of  the  oils  was  determined  by  means 
of  the  Mohr-Westphal  balance.  As  mentioned  before,  the 
fourth  decimal  is  not  to  be  considered  as  rigidly  accurate, 
but  it  gives  a  closer  approximation  to  the  truth  than  if  it  were 
entirely  discarded.  The  temperature  at  which  the  specific 
gravity  was  measured  was  exactly  20°. 

1  Amer.  Chem.  Jour.,  40,  495  (1908). 


33 


Lot. 
No.  of 
tubes. 


Table  IV. — The  First  Fractionation. 

a  3 


Hours1       1 8— 
req.          23— 
Spec. 
Frac.    grav. 

Al  0.8250 
A2  0.8287 

BI    0.8367 

B2  0.8392 
C\  0.8413 
C2  0.8460 
C3  0.8488 
A  0.8470 
D2  0.8495 
D3  0.8514 
A  0.8555 
Et  0.8527 
E2  0.8540 
E3  0.8570 

Lot. 
No.  of 

tubes. 


Hours 
req. 

Spec. 
Frac.    grav. 

Al  0.8295 
A2  0.8315 
#1  0.8375 
B2  0.8413 
C\  0.8418 
C2  0.8442 
C3  0.8495 
A  0.8449 

A  0.8455 
A  0.8490 

E!    0.8500 
0.8510 


14  tubes 
i  tube 
Vol.,2 


cc. 

312 
90 
485 
250 
828 
228 
126 

1014 

375 

200 
172 
720 
430 
4OO 


16 


£2 

E3  0.8567 


Vol., 
cc. 

170 

100 

327 
250 

505 
223 

74 
495 
328 
260 
545 
295 
170 


17  —  8  tubes 


45—  3  tubes 


1 

1 

0 

o 

0 

o 

Spec, 
grav. 

.8285 
.8310 
8370 
8408 

Vol., 
cc. 

73 
59 
218 
78 

s 

g 

0. 
0. 
0. 

o 

pec. 
;rav. 

8223 
8270 
8372 
84.OO 

Vol., 
cc. 

138 

54 
258 
200 

Spec, 
grav. 

0.8233 

o  .  8405 

Vol., 
cc. 

50 
130 

0 

o 

0 

o 

0 

8440 
8442 

8430 
.8464 
.8500 

272 
136 

313 
150 

112 

0. 
0. 
0. 
0. 

o. 

0. 

8442 

8455 
8480 
8488 
8500 
8540 

290 

235 
148 

538 
295 
H5 

0.8505 
0-8535 

0.8546 
0.8619 

120 
65 

235 
30 

0 

0 
0 

•8475 
8509 
.8540 

285 
135 

118 

o. 

0. 
0. 

8537 
8550 
8580 

380 

245 
170 

0.8615 

172 

6 

103 


17—7  tubes 
24 —  i  tube 


17 —  i  tube4 
40 —  3  tubes 


Spec, 
grav. 


O. 
O. 
O. 

0-8453 
0.8419 

o . 84^9 

0.8465 
0-8454 
0.8500 

0.8495 
0.8513 
O. 


Vol., 
cc. 

130 

358 
92 
425 
138 
I30 
640 
I67 
195 

575 
185 
130 


96- 

Spec. 
grav. 

0.8320 
0-8352 
0.8405 
0.8451 
0.8443 
0.8495 

0.8483 
0.8517 

o . 8500 

0.8569 


tube 
Vol., 
cc. 


22 
184 
124 
270 
147 

368 
2IO 

360 

185 


17—  3  tubes 

40 —  i  tube 

150—  i  tube 

Spec.  Vol., 

grav.  cc. 

0.8287         85° 


o .  8490 

0.8485 
0.8441 
0.8507 

o . 8450 
o . 8490 

0.8537 

0.8564 


!34 

35 

218 

67 

302 
132 

215 
174 


1  Chapman  pump  was  run  day  and  night.     Manometer  indicated  pressures  rang- 
ing from  30  to  80  mm. 

2  In  lots  1  to  5,  1000  cc.  of  crude  oil  were  supplied  to  each  tube. 

3  Beginning  with  lot  6,  950  cc.  of  crude  oil  were  supplied  to  each  tube. 

4  The  pressure  in  the  tubes  was  diminished  intermittently. 
«  See  page  17. 


34 


Lot. 
No.  of 
tubes. 

7 
9 

8 

10 

9 

10 

Hours 

20  —  7  tubes 

20  —  i  tube 

19  —  8  tubes 

24  —  2  tubes 

req. 

24  —  i  ti 

ube 

22  2  ti 

.ibes 

40—8 

tubes 

Spec. 

Vol., 

Spec. 

Vol., 

Spec. 

Vol., 

Spec. 

Vol., 

Frac. 

grav. 

cc. 

grav. 

cc. 

grav. 

CC. 

grav. 

cc. 

Al  o 

.8325 

66 

0 

.8175 

45 

0 

.8364 

88 

o 

.8215 

145 

A2  o 

.8356 

30 

0 

•8365 

64 

0 

.8234 

90 

Bl  o 

.8395 

164 

0 

.8333 

no 

0 

.8400 

215 

0 

•8330 

397 

B2  o 

.8418 

140 

0 

.8420 

240 

o 

.8350 

155 

g 

o 

.  8400 

87 

Cl  o 

.8408 

475 

O 

.8417 

132 

O 

•8445 

368 

o 

.8415 

**  / 

350 

C2  o 

.8468 

123 

0 

.8500 

22 

0 

.8467 

225 

o 

.6436 

255 

£, 

.  .  . 

0 

•8495 

82 

0 

.8480 

160* 

Z^1  o 

.8449 

500 

0 

.8468 

no 

0 

.8465 

460 

0 

.8485 

507 

£>2  o 

.8487 

270 

0 

.8498 

1  06 

O 

.8478 

260 

0 

•8495 

280 

o« 

0 

.8500 

260 

0 

•8545 

247 

£j    O 

.8500 

483 

0 

•8533 

228 

0 

.8490 

450 

0 

.8548 

313 

£2    0 

.8524 

3i8 

o 

•8495 

354 

o 

.8550 

275 

E, 

0 

.8521 

233 

0 

.8580 

375 

Lot. 

10 

11 

12 

13 

No.  of 

tubes. 

8 

10 

9 

10 

Hours 

req. 

14 

17 

42 

24  —  8 

tubes 

40  —  2 

tubes 

Spec. 

Vol., 

Spec. 

Vol., 

Spec. 

Vol., 

Spec. 

Vol., 

Frac. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

A!  O 

.8273 

130 

0 

.8258 

215 

0 

.8325 

125 

0 

•8323 

122 

A2  o 

.8288 

75 

0 

.8318 

70 

0 

•8345 

87 

0 

-8352 

96 

£t    0 

•8395 

220 

0 

.8370 

340 

o 

.8430 

235 

0.8438 

245 

#2     0 

.8418 

1  60 

0 

.8480 

1  80 

0 

.8467 

120 

0 

.8470 

180 

Cl  o 

.8423 

240 

0 

.8422 

488 

o 

.8470 

278 

o 

.8464 

317 

C2  o 

.8440 

195 

0 

•8450 

205 

o 

.8487 

288 

0 

.8505 

235 

C8  o 

.8500 

150 

.  .  .  . 

.  .  .  . 

.  .  . 

D!  o 

.8460 

410 

O 

.8465 

565 

o 

•8495 

452 

0 

.8500 

312 

D2  o 

.8475 

2IO 

0 

.8490 

310 

0 

.8522 

305 

0 

.8492 

375 

D3  o 

.8500 

348 

0.8530 

187 

o 

.8518 

150 

El  o 

.8532 

320 

o 

.8510 

297 

0 

.8505 

475 

0 

.8505 

450 

E2  o 

-8535 

282 

o 

.8520 

405 

0 

•8533 

490 

0 

.8489 

395 

E3  o 

.8550 

215 

o 

•8533 

155 

0 

.8518 

1  80 

1  Several  cubic  centimeters  of  this  fraction  were  mixed,  accidently,  with  frac- 
tion E3. 


35 


Lot. 
No.  of 
tubes. 
Hours 
req. 

Frac. 


14 


15 


Spec. 
grav. 


Vol., 
cc. 


26 —  3  tubes 
Spec.  Vol., 
grav.  cc. 


26 —  3  tubes 
Spec.  Vol., 

grav.  cc. 


A  0.8355   i32  0.8381   6o  0.8305   73 
Bl  0.8470   236  0.8487   94  0.8452  143 


Cl 


0.8565 
0.8560 


v-1 

D1  0.8523 

D2  0.8550 

D3 

£t  0.8540 

E2  0.8532 


98 
150 

170 
205 

150 
325 


0.8430  i 10  0.8465  138 

0.8480   57  0.8509  88 

0.8475  212  0.8505  158 

0.8517  104  0.8522  178 

0.8467  184  0.8561  192 

0.8502  152  0.8585  140 


16 

15 

40 —  11 
64 —    4 

Spec, 
grav. 

0.8370 
0.8357 

o . 8449 

0.8445 
0.8475 
0.8509 
0.8562 
0.8540 
0.8530 
0.8575 
0.8538 
0.8562 
0.8595 


tubes 
tubes 
Vol., 


200 
108 
490 
226 

635 

235 

90 

825 

495 
150 

775 
620 
205 


Lot. 
No.  of 
tubes. 
Hours 
req. 

17 

9 

40 

Spec.           Vol., 

18 

8 
24  —  5 
48—2 
64  —  1 

Spec. 

tubes 
tubes 
tube 
Vol., 

19 

10 

40—  8  tubes 
64  —  2  tubes 

Spec.           Vol., 

20 

10 
20  —  6  tubes 
30  —  4  tubes 

Spec.          Vol., 

Frac.     grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

A 

0. 

8258 

225 

o 

.8322 

112 

0.832O 

146 

0 

.8281 

236 

B 

0. 

8432 

452 

0 

•8435 

335 

0.8438 

385 

0 

.8413 

518 

ct 

o. 

8480 

450 

0 

•8495 

250 

0.8480 

300 

0 

.8450 

350 

0. 

8488 

168 

o 

.8500 

250 

0.8472 

315 

0 

•8495 

300 

D\ 

0. 

8530 

520 

o 

•8530 

320 

0.8509 

422 

O 

.8508 

325 

D2 

0. 

8550 

350 

0 

.8540 

350 

0.8535 

355 

0 

-8538 

460 

El 

o. 

8585 

385 

o 

•8547 

902 

0.8492 

580 

0 

.8513 

445 

E2 

0. 

8598 

460 

o 

•8526 

640 

0.8560 

415 

0 

.8540 

550 

1     TI 

—,.-,:„!«  «J        j.1 

.*,  .4   i— 

short  time,  the  reservoirs  were  nearly  two-thirds  exhausted.  The  pump  was  stopped, 
and  the  remainder  of  the  oil  allowed  to  diffuse  during  the  night  under  normal  pressure. 
2  This  irregularity,  *.  «.,  the  liberation  of  oil  with  a  specific  gravity  higher  than 
those  of  the  oils  immediately  following,  is  observed  when  an  amount  of  water  is  added 
sufficient  to  replace  a  very  small  amount  of  oil  for  the  first  fraction. 


Lot.  21 

No.  of 

tubes  10 

Hours1     24 —  6, tubes 
req.         40 —  2  tubes 
64—  2  tubes 
Spec.  Vol., 

Frac.     grav.  cc. 

A  0.8275  245 

B  0.8410  615 

Cl  0.8452  520 

C2  0.8488  226 

D1  0.8512  533 

A  0-8535  4*5 
EI  0.8557  375 
E2  0.8625  282 

Lot.  25 
No.  of 

tubes  9 

Hours2  48 — .  8  tubes 

req.  72 —  1  tube 


Spec. 
Frac.     grav. 

A 
B 


0.8270 
0.8425 
0.8495 
o . 8492 
0.8509 

2  0.8510 

El  0.8556 
E2  0.8570 


D. 


Vol., 
cc. 

225 

410 

752 
250 
320 
480 
335 
395 


29 


Lot. 
No.  of 
tubes  10 

Hours4      18 —  5  tubes 
req.          40 —  5  tubes 


Frac. 

A 
B 


, 

D, 

EF, 
EF, 


Vol., 
cc. 


3327 


22 

10 

40 —  6  tubes 
4  tubes 


Vol. 
cc. 


Spec, 
grav. 

0.8281 

o . 8405 

0.8459 
0.8472 
0.8505 
0-8523 
0.8615 
0.8585 


210 
508 
265 
410 

435 
450 
385 
365 


26 


10 

17 —  2  tubes 

24 —  4  tubes 

41 —  4  tubes 

Spec.         Vol., 

grav.  cc. 

0.8284  315 

0.8422  550 

0.8473  520 

0.8508  178 

0.8515  600 

0.8540  230 

0.8559  490 

0.8586  135 


Spec, 
grav. 

0.8262  3OO 

0-8395  505 

o . 8463  390 

0.8488  270 

0.8520  510 

0.8543  290 

0.8550  417 

0.8559  645 


30 

15 

20—7 
41 — 6 
63—2 

Spec. 

grav. 

0.8348 
0.8468 

o . 8490 

0.8505 
0.8485 
0.8502 
0.8520 
0.8528 


23 

10 

tubes 
52 —  5  tubes 


24 

10 

40 —  4  tubes 
64 —  6  tubes 


Spec, 
grav. 

0.8241 
0-8395 

o . 8448 
o . 8470 

0-8533 
0.8541 
0.8650 
0.8624 

27 


Vol., 
cc. 

330 

615 

420 

305 

400 

465 
305 
350 


Spec, 
grav. 

0.8250 

o . 8408 
o . 8463 

0.8505 
0.8540 
0.8540 
0.8623 

o . 8645 

28 


Vol., 
cc. 

287 

535 
475 
1 86 

525 
360 

393 

335 


10 

17 — 4  tubes 
29 —  6  tubes 


10 

24 —  7  tubes 
28 —  3  tubes 


Spec, 
grav. 

0.8312 

o . 8440 
o . 8460 

0.8478 

o . 8482 
o . 8500 

O.8520 
0.8565 

31 


Vol., 
cc. 

230 
470 

400 
232 

435 
420 

465 

335 


Spec, 
grav. 

0-8333 

o . 8440 

0.8458 

o . 8500 
0.8470 
0.8498 
0.8492 
0.8505 


Vol., 
cc. 

240 
410 

415 
177 

387 

400 

69o3 

600 


32 


tubes 

tubes 

tubes 

Vol., 

cc. 

335 
630 
560 
277 
750 
540 
1125 
880 

5097 


10 
44  —  4  tubes 

15 
40  —  7  tubes 

89  —  6  tubes 

89  —  4  tubes 

103—  4  tubes 

Spec.           Vol., 

Spec.         Vol., 

grav.              cc. 

grav.            cc. 

0.8292       245 

0.8270     445 

0.8439       576 

0.8423       726 

0.8495       465 

0.8500       730 

0.8523       205 

0.8500       2  2O 

0.8517       670 

0-8545       750 

0.8552       210 

0.8543       540 

0.8555       805 

0.8580       870 

0.8610     360 

0.8598       910 

3536 


5191 


1  Pressure  in  the  tubes  was  diminished  intermittently. 

2  Some  oil  of  this  fraction  was  lost. 

3  Beginning  with  lot  28,  fractions  E  and  F  were  collected  together. 

4  Pressure  in  tubes  was  diminished  intermittently. 


37 


Lot. 
No.  of 

33 

34 

35 

tubes. 

10 

10 

9 

Hours' 

41—4  tubes 

44  —  6  tubes 

48—  6  tubes 

req. 

65  —  4  tubes 

68—  4  tubes 

72—  3  tubes 

89  —  2  tubes 

Spec.               Vol., 

Spec.              Vol., 

Spec.              Vol., 

Frac. 

grav.                cc. 

grav.                cc. 

grav.                cc. 

A 

0.8330          290 

0-8355          320 

0.8380          235 

Bt 

o  .  8440       365 

0.8475          525 

0.8460         452 

B, 

0.8462          165 

ct 

0.8502          500 

0.8508          470 

0.8508       345 

C2 

0.8540       160 

0.8543          190 

0.8525       245 

Dl 

0.8555     655 

0-8575          530 

0.8549       580 

D, 

0.8562     250 

0.8585          325 

0-8573       335 

EFt 

0.8575       735 

0-8535          895 

0-8557       645 

EF, 

0.8585       480 

0.8555          405 

0.8570       492 

3600 


3660 


3329 


Observations  on  the  First  Fractionation. 


Specific  Gravity. — The  range  of  the  specific  gravity  ex- 
tended from  0.8175,  the  value  for  Fraction  Al  of  Lot  7,  to 
0.8650,  the  value  for  Fraction  E±  of  Lot  13.  The  value  for 
the  crude  oil  itself  was  0.8375.  The  limits  of  the  specific 
gravities  of  the  individual  lots  averaged  from  0.820  to  0.860. 
The  specific  gravity  decreases  gradually  from  E  to  B,  but  be- 
tween B  and  A ,  the  decrease,  in  most  of  the  lots,  is  much  greater 
than  between  any  two  consecutive  lower  fractions.  This 
marked  change  was  also  observed  in  the  study  of  the  diffusion 
of  benzene  in  solution.  A  detailed  investigation  into  the 
cause  of  this  sudden  divergence  will  be  undertaken  in  the 
near  future. 

Color. — The  colors  of  the  fractions  obtained  extended  from 
green  to  black.  The  lighter  oils  possessed  a  beautiful  green 
fluorescent  color,  which  shaded  gradually  to  brown,  and  then 
to  the  deep  black  of  the  heavier  oils. 

Odor. — The  unpleasant  odor  of  the  crude  petroleum  disap- 
peared almost  entirely  in  the  oils  of  Fraction  A  and  B ;  but  the 
other  fractions  still  possessed  to  a  greater  or  less  extent  the 
odor  of  the  natural  oil. 

The  Volume  of  Oil  Retained  by  the  Fuller's  Earth. — The 
amount  of  oil  retained  by  the  earth  averaged  about  55  per 


38 

cent,  of  the  amount  supplied.  In  the  first  fractionation  of 
the  crude  Pennsylvania  oil,  specific  gravity  0.810,  Gilpin 
and  Cram  found  that  approximately  40  per  cent,  of  the  oil 
was  retained  by  the  earth.  It  is  evident,  therefore,  that  the 
amount  of  oil  remaining  in  the  earth  depends  chiefly  upon  the 
character  of  the  oil.  The  Pennsylvania  petroleum  contains 
a  much  smaller  percentage  of  unsaturated  hydrocarbons, 
sulphur,  and  asphaltic  substances  than  the  Illinois  oil  em- 
ployed in  this  investigation.  Since  the  fuller's  earth,  as  will 
be  shown  later,  readily  removes  these  substances  in  the  process 
of  fractionation,  the  large  percentage  of  Illinois  oil  retained 
by  the  earth  is  thus  clearly  explained.  It  is  safe  to  conclude 
that  if  the  heavy  Texas  or  California  oil  were  allowed  to  diffuse 
through  fuller's  earth,  the  amount  of  oil  retained  would  ex- 
ceed the  amounts  of  either  of  the  above-mentioned  oils  lost 
in  the  earth. 

The  Second  Fractionation. 

The  products  obtained  from  the  first  fractionation  were 
united  according  to  the  following  arrangement : 

Specific  gravity  of  the  Specific  gravity  of 

Lot.  oils  united.  mixture. 

36  0.8250-0.8350  0.8293 

37  0.8350-0.8400  0.8390 

38  o . 8400-0 . 8450  o . 8433 

39  0.8400-0.8450  0.8433 

40  o . 8450-0 . 8500  o . 8490 
41 

42 

43 

44         0.8500-0.8600         0.8543 

45 

U  It  (I 

(I  (I  U 

48 

49 
50 


46 
47 

«        a  .    u 

(I  (I  U 

u        (i  u 


The  oils  thus  combined  were  subjected  to  chilling  and  filtra- 
tion for  the  purpose  of  removing  as  much  dissolved  paraffin 


39 

as  possible.  The  procedure  was  as  follows :  The  oils  were  first 
chilled  at  temperatures  ranging  from  o°  to  10°  and  then  filtered 
through  plaited  filter  papers.  When  the  oil  ceased  to  drip 
from  the  funnel,  the  residue  upon  the  filter  paper  was  placed 
in  a  larger  filter  press,  and  the  remaining  oil  separated  by 
pressure  from  the  paraffin.  The  filter  press  was  simple  in 
construction.  A  piston,  fitted  closely  in  an  iron  cylinder, 
was  gradually  forced  down  upon  the  oil-laden  paraffin,  which 
rested  upon  a  membrane  of  cotton  duck  fastened  between 
perforated  tin  supports.  The  retained  oil  was  forced  through 
the  membrane  and  was  collected  from  the  outlet  below.  The 
lighter  oils  deposited  very  little  paraffin;  from  the  heavier 
ones  somewhat  more  paraffin  was  separated.  Owing  to  the 
high  viscosity  of  the  heavier  oils,  the  filtration  proceeded 
very  slowly.  Since  too  much  time  was  consumed  in  this 
process,  the  paraffin  of  some  of  the  oils  of  Fraction  E  was  not 
removed.  A  slight  change  in  specific  gravity  occurred  in  the 
oils  from  which  the  paraffin  was  removed. 

The  final  specific  gravities  of  the  united  oils  were  as  fol- 
lows : 

Lot.  Specific  gravity. 

36  0.8305  Paraffin  removed. 

37  0.8415 

38  o .  8433  Paraffin  not  removed. 

39  0.8455  Paraffin  removed. 

40  0.8515 

41  0.8515 

42  0.8515 

43  0.8540 

44  0.8543  Paraffin  not  removed. 
45-                 0.8543 

46  0.8543 

47  0.8543 

48  0.8543 

49  0.8557  Paraffin  removed. 

50  0.8557 

When  these  oils  were  again  allowed  to  diffuse  upward 
through  fuller's  earth,  the  following  fractionation  was  ob- 
tained : 


Table  V. — The  Second  Fractionation. 


Lot.                    36 
No.  of 
tubes.                    5 
Hours1        44  —  3  tubes 
req.             48  —  2  tubes 

37 

4 
51 

38 

8 
48—  7  tubes 
64  —  1  tube 

39 

8 
29  —  4  tubes 
45  —  3  tubes 
64  —  1  tube 

Spec. 

Vol., 

Spec. 

Vol.,  ' 

Spec. 

Vol., 

Spec. 

Vol., 

Frac. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

A 

0.8272 

1  60 

0 

.8292 

135 

O 

.8331 

180 

0.8290 

255 

6, 

0.8315 

216 

0 

.8421 

215 

0 

.8447 

175 

0.8432 

355 

B2 

0.8331 

58 

O 

•8455 

210 

0-8458 

no 

Q 

0-8334 

350 

0 

.8467 

295 

0 

.8490 

305 

o  .  8492 

455 

c% 

0-8355 

85 

0 

.8505 

175 

0.8513 

1  80 

D, 

0.8330 

360 

o 

.8468 

340 

0 

.8492 

4OO 

0.8505 

740 

D2 

0-8339 

320 

0 

•8485- 

152 

0 

.8509 

295 

0.8527 

275 

EF, 

0-8347 

72O 

0 

.8480 

535 

o 

.8508 

710 

0.8546 

1166 

EF2 

0-8356 

320 

0 

.8489 

215 

0 

.8518 

355 

0.8560 

350 

2589 


1887 


3886 


2805 


Lot. 
No.  of 
tubes. 
Hours 
req. 

40 

9 

48  —  5  tubes 
72  —  4  tubes 
Spec.           Vol., 

41 

5 
40 

Spec. 

Vol., 

42 

5 
69 

Spec. 

Vol., 

43 

4 
10  days  —  2 
17  days  —  2 
Spec. 

tubes 
tubes 
Vol., 

Frac. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

A 

0.8305 

380 

O 

,83l6 

235 

o 

•  8325 

210 

0 

.8435 

65 

Bl 

0.8438 

515 

0 

.8460 

290 

O 

.8487 

265 

0 

.8546 

115 

B2 

0-8453 

155 

o 

.8480 

65 

o 

.8515 

54 

.  .  .  . 

Q 

0.8518 

600 

0 

8523 

375 

'o 

,8540 

335 

0 

.8575 

20O 

Q 

0-8539 

170 

o 

.8540 

100 

O 

.8567 

56 

A 

0.8550 

685 

0 

.8558 

470 

0 

.8572 

420 

O 

.8605 

220 

ft 

0.8560 

330 

o 

.8571 

no 

o 

.8582 

175 

0 

.8640 

50 

EFl 

0.8605 

780 

o 

.8620 

580 

0 

.8640 

675 

0 

.8650 

225 

EF2 

0.8620 

600 

0 

,8622 

320 

o 

8650 

200 

0 

.8615 

78 

2420 


953 


4215        2545 

»  In  this  series,  as  well  as  those  following,  the  pressure  in  the  tubes  was  dimin- 
ished intermittently. 


Lot. 
No.  of 
tubes. 
Hours 

44 

3 
48  —  2    tubes 

45 

5 
66 

46 

5 
93 

47 

5 
13  days1 

req. 

96  —  1  tube 

Spec.         Vol., 

Spec. 

Vol., 

Spec. 

Vol., 

Spec. 

Vol., 

Frac. 

grav.           cc. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

A            0 

•8330         85 

0.8362 

170     o 

.8332 

210 

0.8340 

145 

B1       o 

.8505       175 

0.8510 

210      0 

.8480 

260 

o  .  8500 

275 

£, 

O.8522 

80    o 

.8505 

5O 

C\       o 

•8582       I55 

0.8562 

265     o 

•8554 

300 

0.8553 

320 

C2       o 

.8605          65 

0.8585 

50     o 

.8567 

95 

0.8576 

50 

Pt         0 

.8605       195 

0.8567 

425     o 

.8600 

370 

0-8595 

430 

A     o 

.8620       120 

0.8580 

100      0 

.8613 

1  20 

0.8618 

70 

£F,    o 

.8672       240 

0.8659 

615     o 

.8666 

610 

0.8665 

330 

£F2    o 

.8680       175 

0.8670 

150    o 

.8680 

130 

0.8670 

215 

1210 

2065 

2145 

1835 

Lot. 

48 

49 

50 

No.  of 

tubes. 

5 

7 

5 

Hours 

14  days2 

48 

72—  4  tubes 

req. 

89—  1  tu 

be 

Spec. 

Vol., 

Spec. 

Vol., 

Spec.             Vol., 

Frac. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

A 

0.8385 

125 

0.8341 

255 

O 

.8320 

170 

B, 

0.8530 

275 

0.8505 

395 

0 

.8485 

230 

S, 

0.8520 

95 

0 

.8500 

70 

c, 

0.8568 

320 

0.8560 

380 

O 

•8565 

300 

C2 

0.8586 

90 

0.8572 

230 

0 

•8577 

IOO 

0, 

0.8610 

325 

0.8620 

500 

0 

.8609 

480 

A 

0.8623 

115 

0.8625 

290 

o 

.8626 

125 

EF, 

0.8695 

330 

0.8705 

500 

0 

.8685 

640 

EF2 

o  .  8700 

80 

0.8705 

580 

0 

.8700 

235 

1660 


3225 


2350 


Observations  on  the  Second  Fractionation. 


Specific  Gravity. — The  range  of  the  specific  gravities  grows 
smaller  as  the  oils  to  be  fractionated  become  lighter,  and  less 
complex.  Thus,  in  Lot  36,  the  range  of  specific  gravity  ex- 
tends from  0.8272,  the  value  for  Fraction  A,  to  0.8356,  the 

1  Owing  to  the  weakness  of  the  water  pressure,  the  pressure  in  the  tubes  was  only 
slightly  diminished.     The  tubes  were  taken  down  before  the  reservoirs  were  com- 
pletely exhausted.     The  distances  to  which  the  oil  had  risen  were  35,  25,  30,  20,  10 
cm.  from  the  tops  of  the  tubes. 

2  Owing  to  the  weakness  of  the  water  pressure,  the  pressure  in  the  tubes  was  di- 
minished  but   slightly   during   this   time.     The   tubes  were   taken   down   before   the 
reservoirs  were  completely  exhausted.     The  distances  to  which  the  oil  had  risen  were 
50,  35,  30,  60,  55  cm.  from  the  tops  of  the  tubes. 


value  for  EF2,  the  difference  between  them  being  0.0084. 
In  Lot  38,  the  mother  oil,  of  specific  gravity  0.8433,  yielded 
fractions  whose  specific  gravities  ranged  from  0.8331  to 
0.8518,  amounting  to  a  difference  of  0.0187.  This  fact  ap- 
pears to  be  general  throughout  the  various  lots,  and  points 
to  the  gradual  formations  of  mixtures  which  will  pass  through 
the  earth  unaltered,  just  as  the  fractionation  by  distillation 
tends  to  yield  substances  with  definite  boiling  points. 

Color. — The  color  of  the  oils  in  this  fractionation  shaded 
from  a  very  light  yellow  to  greenish  black. 

Odor. — The  odor  of  the  crude  petroleum  vanished  com- 
pletely from  the  oils  of  this  fractionation. 

Volume  of  Oil  Retained  by  the  Earth. — The  oil  retained  by 
the  earth  in  this  fractionation  amounted  to  approximately 
50  per  cent.,  a  smaller  percentage,  as  is  naturally  to  be  ex- 
pected, than  in  the  fractionation  of  the  crude  petroleum. 

The  Third  Fractionation. 

The  following  oils  obtained  from  the  second  fractionation 
were  united  for  the  third  fractionation: 


Lot  51. — Specific  Gravity  0.8316. 


Specific     Volume, 


Specific 


Volume, 


Lot.  Fraction. 

gravity. 

cc. 

Lot.  Fraction. 

gravity. 

cc. 

36 

A 

0.8272 

1  60 

42 

A 

O. 

8325 

210 

39 

A 

0.8290 

255 

44 

A 

0 

8330 

85 

37 

A 

O.8292 

135 

36 

BZ 

O 

8331 

58 

40 

A 

0-8305 

380 

38 

A 

0 

8331 

1  80 

36 

B* 

0.8315 

216 

46 

A 

0 

8332 

210 

41 

A 

0.8316 

235 

36 

Cl 

0 

8334 

350 

50 

A 

0.8320 

170 

49 

A 

0 

8341 

255 

2899 


Lot  52.  —  Specific  Gravity  0.8343. 


Lot.   Fraction. 


Specific       Volume, 

gravity.  cc.  Lot.     Fraction. 


36 
36 

47 


D 


0.8330  360 
0.8339  320 
0.8340  145 


36 
36 
36 


EFl 
EF2 
C2 


Specific  Volume, 

gravity.  cc. 

0.8347  720 

0.8356  320 

0.8355  85 


1950 


43 


Lot  53.  —  Specific 

Gravity  0.8433. 

Specific 

Volume, 

Specific 

Volume, 

Lot. 

Fraction. 

gravity. 

cc. 

Lot. 

Fraction. 

gravity. 

cc. 

45 

A 

0.8362 

170 

38 

B, 

0.8447 

175 

48 

A 

0.8385 

125 

40 

B, 

0-8453 

155 

37 

Bl 

0.8421 

215 

38 

B, 

0-8455 

2IO 

39 

BI 

0.8432 

355 

39 

B, 

0.8458 

50 

40 

B 

0.8438 

515 

1970 

Lot  54.  —  Specific 

Gravity  0.8473. 

Specific 

Volume, 

Specific 

Volume, 

Lot. 

Fraction. 

gravity. 

cc. 

Lot. 

Fraction. 

gravity. 

cc. 

39 

B2 

0.8458 

60 

50 

B, 

0.8485 

230 

B. 

o  .  8460 

290 

42 

0.8487 

265 

37 

0.8467 

295 

39 

cl 

o  .  8492 

455 

B\ 

0.8480 

65 

38 

Ci 

o  .  8490 

305 

1965 

Lot  55.  —  Specific 

Gravity  0.8485. 

Specific 

Volume, 

Specific 

Volume, 

Lot. 

Fraction. 

gravity. 

cc. 

Lot. 

Fraction. 

gravity. 

cc. 

37 

•Pi 

0.8468 

340 

37 

EF, 

0.8489 

215 

37 

D, 

0.8485 

152 

38 

Dt 

o  .  8492 

400 

37 

EFl 

0.8480 

535 

47 

B, 

o  .  8500 

275 

1917 

Lot  56.  —  Specific 

Gravity  0.8508. 

Specific 

Volume. 

Specific 

Volume, 

Lot. 

Fraction. 

gravity. 

cc. 

Lot. 

Fraction. 

gravity. 

cc. 

50 

B2 

o  .  8500 

70 

45 

B, 

0.8510 

210 

49 

B, 

0.8505 

395 

39 

c* 

0.8513 

1  80 

44 

0.8505 

175 

42 

B, 

0.8515 

54 

46 

B2 

0.8505 

50 

40 

0.8518 

600 

38 

C2 

0.8505 

175 

1909 

Lot  57.  —  Specific 

Gravity  0.8509. 

Specific 

Volume, 

Specific 

Volume, 

Lot. 

Fraction. 

gravity. 

cc. 

Lot. 

Fraction. 

gravity. 

cc. 

38 

A 

0.8505 

740 

38 

A 

0.8509 

295 

39 

EF1 

0.8508 

710 

38 

EF2 

0.8518 

355 

2100 


44 


Lot  58.—  Specific 

Specific        Volume, 

Gravity  0.8558. 

Specific 

Volume* 

Lot. 

Fraction. 

gravity. 

cc. 

Lot.  Fraction. 

gravity. 

cc. 

49 

B2 

0.8520 

95 

49 

c, 

0.8560 

380 

45 

B2 

0.8522 

80 

45 

c, 

0.8562 

265 

0.8523 

375 

50 

c, 

0.8565 

300 

48 

&t 

0.8530 

275 

42 

c, 

0.8567 

56 

4° 

C2 

0-8539 

170 

46 

c, 

0.8567 

95 

42 

c, 

o  .  8540 

335 

48 

C,          0.8568 

320 

0.8540 

100 

49 

c, 

0.8572 

230 

47 

c, 

0-8553 

320 

43 

c, 

0.8575 

200 

46 

c, 

0-8554 

300 

3896 

Lot  59.  —  Specific 

Gravity  0.8563. 

Specific 

Volume, 

Specific 

Volume.. 

Lot. 

Fraction. 

gravity. 

cc. 

Lot. 

Fraction. 

gravity. 

cc. 

39 

EF, 

o  .  8546 

166 

41 

ft 

0 

.8571 

1  10 

40 

D, 

0.8550 

685 

42 

D! 

0 

.8572 

420 

41 

Dt 

0.8558 

470 

45 

D, 

O 

.8580 

100 

39 

EF, 

0.8560 

350 

42 

D, 

0 

.8582 

175 

40 

D, 

0.8560 

330 

48 

c, 

O 

.8586 

90 

45 

D, 

0.8567 

425 

47 

D, 

0 

•  8595 

430 

4750 

Lot  60.  —  Specific 

Gravity  0.8615. 

Specific 

Volume, 

Specific 

Volume, 

Lot. 

Fraction. 

gravity. 

cc. 

Lot. 

Fraction. 

gravity. 

cc. 

46 

£>t 

0  .  8600 

370 

41 

EF, 

O 

.8620 

580 

49 

EFi 

o  .  8605 

780 

44 

ft 

0 

.8620 

120 

43 

n 

0.8605 

220 

49 

ft 

0 

.8620 

500 

44 

Dl 

o  .  8605 

195 

EF, 

0 

.8622 

320 

50 

n 

o  .  8609 

480 

48 

D, 

0 

.8623 

115 

48 

D, 

0.8610 

325 

49 

D, 

O 

.8625 

290 

46 

0.8613 

120 

50 

D, 

0 

.8626 

125 

47 

D2 

0.8618 

70 

42 

E, 

o 

.8640 

675 

4° 

EF2 

0.8620 

600 

5880 

Lot  61.  —  Specific 

Gravity  0.8680. 

Specific 

Volume, 

Specific        Volume 

Lot. 

Fraction. 

gravity. 

cc. 

Lot. 

Fraction. 

gravity. 

cc. 

42 

EF2 

0.8650 

200 

46 

EF, 

0 

.8680 

130 

43 

EF, 

0.8650 

225 

44 

EF, 

O 

.8680 

175 

45 

EF, 

0.8659 

615 

5° 

EF, 

0 

.8685 

640 

47 

0.8665 

330 

48 

EF, 

0 

.8695 

330 

46 

EF\ 

0.8666 

610 

50 

EF, 

0 

.8700 

235 

47 

EF2 

0.8670 

215 

49 

EF, 

0 

.8705 

500 

45 

EF, 

0.8670 

150 

49 

EF, 

o 

.8705 

580 

44 

EF, 

0.8672 

240 



4975 


45 

The  oils  thus  united   were   fractionated   by   fuller's  earth 
again,  with  the  results  given  in  Table  VI. 


Table  VI.— The  Third  Fractionation. 


Lot. 
No.  of 
tubes. 
Hours 
req. 

51 
31 

60 
Spec.          Vol., 

52 
2 

60 
Spec. 

Vol., 

53 
2 

48 
Spec. 

Vol., 

54 
2 

48 
Spec. 

Vol., 

Frac. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

A 

0 

.8213 

92 

0 

.8219 

65 

O 

.8266 

73 

0.8303 

66 

B 

0 

.8303 

185 

0 

.8333 

143 

0 

.8431 

0.8488 

JI5 

Cl 

O 

•8337 

165 

O 

•8375 

190 

O 

.8464 

175 

0.8518 

175 

C2 

o 

.8345 

90 

Dl 

0 

-8353 

210 

0 

'8388 

188 

0 

.8468 

145 

0-8523 

1  60 

D2 

o 

.8356 

170 

O 

•8393 

90 

o 

.8474 

115 

0.8528 

105 

E1 

o 

.8366 

385 

0 

•8403 

175 

0 

.8473 

202 

0-8530 

245 

E2 

0 

.8411 

92 

0 

.8488 

73 

0.8548 

60 

Fi 

o 

8373 

190 

O 

•8431 

88 

o 

.8496 

170 

0.8548 

H5 

1487 

1031 

1068 

1091 

Lot. 

55 

56 

57 

58 

No.  of 

tubes. 

2 

2 

2 

4 

Hours2 

48—  1 

tube 

96 

96 

72—3 

tubes 

req. 

72—  1 

tube 

92—  1 

tube 

Spec. 

Vol., 

Spec. 

Vol., 

Spec. 

Vol.. 

Spec. 

Vol., 

Frac. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

A 

O 

8283 

58 

O 

8313 

75 

0 

.8336 

55 

0.8318 

170 

B 

0 

8457 

100 

0 

.8488 

135 

0 

.8491 

130 

0-8531 

260 

Cl 

0 

8515 

155 

0 

8546 

170 

o 

•8528 

1  80 

0.8578 

205 

C2 

0.8592 

105 

D, 

0 

8521 

220 

0 

8553 

150 

o 

.8551 

'185 

0.8588 

205 

D2 

0 

8543 

50 

0 

8560 

92 

o 

•8573 

45 

0-8593 

340 

El 

O 

8540 

270 

o 

8553 

145 

o 

.8568 

170 

o  .  8603 

325 

E2 

0 

8563 

90 

0 

.8588 

70 

0.8613 

170 

F 

0 

8566 

1  80 

0 

8575 

130 

0 

.8611 

170 

0.8628 

275 

1033 

987 

1005 

2055 

1  The  tin  tubes  used  in  these  lots  were  1.5  inches  in  diameter. 

2  The  pressure  in  the  tubes  was  diminished  intermittently. 


46 


Lot.  59  60  61 

No.  of 

tubes.  5  65 

Hours 

req. 

Frac. 

A 
B 


72 
Spec, 
grav. 

Vol., 
cc. 

72 
Spec, 
grav. 

Vol., 
cc. 

5  days.1 
Spec.     Vol. 
grav.      cc. 

0. 

8328 

195 

0 

.8343 

195 

0.8413   .. 

0. 

8508 

340 

0 

.8540 

330 

O 

.8601  .. 

O. 

8578 

325 

0 

.8601 

290 

O 

.8683  .. 

0. 

8588 

112 

0 

.86l8 

130 

O. 

8608 

490 

O 

.8628 

440 

O 

.8709  .. 

0. 

8623 

135 

0 

.8638 

85 

.  .  .  . 

0. 

8628 

475 

O 

.8664 

425 

0 

8688   .. 

0. 

8633 

155 

0 

.8683 

140 

0. 

8673 

330 

0 

-8703 

310 

O 

8691   .. 

A 

A 


Observations  on  the  Third  Fractionation. 

Specific  Gravity. — The  decrease  in  the  range  of  specific 
gravity  as  the  oils  supplied  become  lighter  is  observed  in  this 
fractionation  as  in  the  preceding  ones. 

Color. — The  lightest  oils  were  almost  colorless;  the  heavier 
oils  were  dark  brown  to  green. 

Odor. — Most  of  the  oils  possessed  an  agreeable  odor. 

Prolonged  Diffusion. — In  Lot  61,  the  time  required  for  the 
oils  to  reach  the  tops  of  the  tubes  was  five  days.  No  frac- 
tionation, as  is  evident  from  an  examination  of  the  specific 
gravities,  occurred  in  the  lower  parts  of  the  tubes.  The  heavier 
oils  of  fractions  D,  E,  and  F  were  exceedingly  viscous. 

Volume  of  Oil  Retained  by  the  Earth.— -The  volume  of  oil 
retained  by  the  earth  in  this  fractionation  amounted  to  ap- 
proximately 45  per  cent.  The  increase  in  the  yield  of  oil  indi- 
cates, therefore,  a  process  of  purification,  in  which,  as  will  be 
shown  later,  such  compounds  as  the  unsaturated  hydrocar- 
bons are  removed. 

The.  Fourth  Fractionation. 

The  following  fractions  obtained  from  the  third  fractiona- 
tion were  united  for  the  fourth  fractionation : 

1  See  below,  this  page. 


47 


Lot  62. — Specific  Gravity  0.8298. 


Specific       Volume, 

Specific 

Volume, 

Lot. 

Fraction. 

gravity.            cc.         Lot.     Fraction 

gravity. 

cc. 

51 

A 

0.8213             92 

51       B 

o  •  8303 

185 

52 

A 

0.8219            65 

56       A 

0-8313 

75 

53 

A 

0.8266         73 

58       A 

0.8318 

170 

55 

A 

0.8283         66 

59       A 

0.8328 

195 

54 

A 

0.8303         58 

979 

Lot  63.  —  Specific 

Gravity  0.834.3. 

Specific        Volume, 

Specific 

Volume, 

Lot. 

Fraction. 

gravity.              cc. 

Lot.  Fraction 

gravity. 

cc. 

52 

B 

0.8333          143 

51     c2 

0-8345 

90 

57 

A 

0.8336         55 

3i       A 

0.8353 

210 

Ci 

0.8337       185 

51     A 

0.8356 

170 

60 

A 

0.8343       195 

1048 

Lot  64.  —  Specific 

Gravity  0.8368. 

Specific       Volume, 

Specific 

Volume, 

Lot. 

Fraction. 

gravity.           cc. 

Lot.  Fraction. 

gravity. 

cc. 

51 

£, 

0.8366          388 

52     c, 

0-8375 

190 

51 

F 

0.8372          190 

52      D, 

0.8388 

188 

956 

Lot  65.  —  Specific 

Gravity  o. 

84.30. 

Specific       Volume, 

Specific 

Volume, 

Lot. 

Fraction. 

gravity.            cc. 

Lot.    Fraction.           gravity. 

cc. 

52 

D, 

0-8393             90 

52       F 

0-8431 

88 

52 

E, 

0.8403          175 

55       Bl 

0-8457 

100 

52 

0.8411             92 

53       Q 

o  .  8464 

175 

53 

B! 

0.8431          115 

53       A 

0.8468 

980 

Lot  66.  —  Specific 

Gravity  o, 

,8483. 

Specific        Volume, 

Specific 

Volume, 

Lot. 

Fraction. 

gravity.               cc. 

Lot.  Fraction 

gravity. 

cc. 

53 

fSj 

0.8473          202 

56       Bl 

0.8488 

135 

53 

A 

0.8474          115 

53       E2 

o  .  8488 

73 

54 

Bl 

0.8488          115 

59       B,. 

0.8508 

330 

970 

Lot  67.  —  Specific 

Specific      Volume, 

Gravity  o 

'85I3- 
Specific 

Volume, 

Lot. 

Fraction. 

gravity.           cc. 

Lot.     Fraction.          gravity. 

cc. 

57 

Bl 

0.8491          130 

54       Q 

0.8518 

175 

59 

BI 

0.8508         10 

55       A 

0.8521 

220 

55 

Cl 

0-8515          155 

58       B, 

0.8531 

26O 

950 


48 


Lot  68. — Specific  Gravity  0.8533. 


Lot. 

Fraction. 

Specific 
gravity. 

Volume, 
cc. 

Lot.  Fraction. 

Specific 
gravity. 

Volume 
cc. 

54 

A 

0.8523 

1  80 

54       ^i 

0.8530 

245 

54 

D2 

0.8528 

105 

60       B 

0-8540 

330 

57 

c, 

0.8528 

1  80 

1040 

Lot  60.  —  Specific 

Gravity  0.8556. 

Specific 

Volume, 

Specific 

Volume  > 

Lot. 

Fraction. 

*.  gravity. 

cc. 

Lot.   Fraction. 

gravity. 

cc. 

55 

EI 

o  .  8540 

270 

56       E, 

0.8553 

H5 

55 

A 

0-8543 

50 

56       D2 

0.8560 

92 

56 

c, 

0.8546 

170 

56      E2 

0.8563 

90 

54 

E2 

0.8548 

60 

55       F 

0.8566 

1  80 

54 

F 

0.8548 

145 

57       El 

0.8568 

170 

57 

n 

0.8551 

185 

57       A 

0-8573 

45 

56 

Di 

0.8553 

150 

56       F 

0-8575 

130 

1882 

Lot  70.— 

-Specific 

Gravity  0.8596. 

Specific 

Volume, 

Specific 

Volume 

Lot. 

Fraction. 

gravity. 

cc. 

Lot.  Fraction. 

gravity. 

cc. 

58 

ct 

0.8578 

205 

60      Cj 

0.8601 

290 

59 

ct 

0-8578 

325 

58      E, 

o  .  8603 

325 

58 

D 

0.8588 

205 

59       A 

o  .  8608 

490 

59 

C2 

0.8588 

112 

57       F 

0.86II 

170 

57 

E,  ' 

0.8588 

70 

58       E2 

0.8613 

170 

58 

0.8592 

105 

60       C2 

0.8618 

130 

58 

D 

0-8593 

340 

2937 

Lot  71.  —  Specific 

Gravity  0.8638. 

Specific 

Volume 

Specific 

Volun 

Lot. 

Fraction. 

gravity. 

cc. 

Lot.    Fraction. 

gravity. 

cc. 

59 

D2 

0.8623 

135 

60      D2 

0.8638 

85 

60 

A 

0.8628 

440 

59      E2 

0.8633 

155 

59 

0.8628 

475 

60      El 

o  .  8664 

425 

-Q 

zr 

^     QA/-.Q 

*%**!» 

1990 


49 
Table  VII. — The  Fourth  Fractionaiion. 

Lot.  62  63  64  65 

No.  of 

tubes.  1111 

Hours 


req. 

72 
Spec. 

Vol., 

72 
Spec. 

Vol., 

90 

Spec. 

Vol., 

48 
Spec. 

Vol., 

Frac. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

grav. 

cc. 

A 

O 

8243 

32 

0.8273 

45 

0. 

8297 

41 

O 

.8308 

42 

B 

0.8298 

71 

0-8357 

75 

O. 

8378 

57 

0 

.8428 

70 

C 

0. 

8323 

90 

0.8378 

95 

0. 

8401 

81 

0 

.8463 

92 

D 

O 

8330 

115 

0-8383 

130 

0. 

8408 

H5 

O 

•8473 

130 

E 

0, 

8333 

130 

0.8388 

98 

O. 

8413 

135 

0 

.8471 

130 

F 

0. 

8341 

75 

0-8393 

95 

0. 

8418 

70 

0 

.8485 

80 

513  538  499  544 

Observations  on  the  Fourth  Fractionation. 

Specific  Gravity. — As  in  the  preceding  fractionations,  the 
decrease  in  the  range  of  specific  gravity  as  the  mother  oils 
become  lighter  is  again  observed  in  this  fractionation.  It 
is  evident,  moreover,  that  there  is  a  constant  forward  ac- 
cumulation towards  definite  and  constant  mixtures.  The 
lighter  oils  of  one  lot  are  found  to  possess  specific  gravities 
closely  approaching  those  of  the  heavier  oils  of  the  preceding 
lot. 

Color. — The  oils  of  Fraction  A  were  almost  colorless;  the 
color  of  the  heavier  oils  ranges  from  green  to  light  brown. 

Odor. — All  the  oils  of  this  fractionation  possessed  agreeable 
odors. 

Volume  of  Oil  Retained. — The  volume  of  oil  retained  by 
the  earth  amounted  to  approximately  40  per  cent. 

Deposition  of  Paraffin. — In  Fractions  A  and  B  of  several 
of  the  lots,  a  fine,  crystalline  deposit  separated  out,  and  col- 
lected upon  the  bottom  of  the  bottles  containing  the  oils. 
When  the  oils  were  warmed,  this  deposit  dissolved  completely, 
showing  it  to  be  paraffin. 

Chemical  Examination  of  the  Fractionated  Oils.     U maturated 
Hydrocarbons. 

Action  of  Concentrated  Sulphuric  Acid. — The  percentage  of 
volume  of  oil  absorbed  by  concentrated  sulphuric  acid  (specific 


50 

gravity  1.84)  was  determined  according  to  the  following  pro- 
cedure: Ten  cc.  of  the  oil  to  be  examined  were  measured  into 
a  glass-stoppered  bottle,  and  thirty  cc.  of  concentrated  sul- 
phuric acid  were  added.  The  mixture  was  thoroughly  shaken 
in  a  machine  for  thirty  minutes  and  then  poured  into  a  burette. 
After  allowing  sufficient  time  for  any  oil  that  might  be  mechan- 
ically absorbed  in  the  acid  to  rise  to  the  top,  the  volume  of  un- 
absorbed  oil  was  read  directly  over  the  acid.  Owing  to  the 
formation  of  heavy  emulsions,  no  attempt  was  made  to  neu- 
tralize and  wash  the  oil. 

The  results  of  the  analyses  are  given  in  the  table  below : 

Per  cent.  Per  cent. 

by  volume  by  volume 

Lot.          Fraction.  absorbed.  Lot.          Fraction.  absorbed. 

5i  A  2.3  51  D1  11.5 

51  B  6.1  51  D2  12.0 

51  Cl  9-1  5i  E  12.5 

51  C2  10.2  51  F  14.5 

Action  of  Bromine. — The  method  employed  for  determining 
the  amount  of  bromine  absorbed  by  the  oils  was  as  follows: 
Between  0.5  and  0.9  of  a  gram  of  the  oil  to  be  examined  was 
dissolved  in  10  to  15  cc.  of  carbon  tetrachloride.  Five  cc.  of 
a  standard  solution  of  bromine  in  carbon  tetrachloride  were 
then  introduced,  and  the  solution  allowed  to  remain,  with  oc- 
casional shaking,  in  a  dark  place  for  30  minutes.  Ten  cc.  of 
a  10  per  cent,  solution  of  potassium  iodide  were  then  added, 
and  the  amount  of  iodine  liberated  determined  immediately 
by  titrating  with  a  standard  solution  of  sodium  thiosulphate. 
A  few  drops  of  a  starch  solution  were  introduced  to  mark  ac- 
curately the  end  of  the  titration.  The  amounts  of  bromine 
absorbed  by  addition  and  substitution  were  not  estimated 
separately. 

The   amount   of   bromine   absorbed,    calculated    upon   the 
basis  of  loo  grams  of  oil,  are  given  in  the  following  table: 
Table  VIII. — First  Fractionation. 


Lot.  Fraction. 

32  A 

32  B 

32  C 


Per  cent, 
of  bromine 
absorbed. 

Lot.         Fraction. 

Per  cent, 
of  bromine 
absorbed. 

5.02 
6.96 
7.40 

32           D 
32           E 
Crude  oil 

7-87 

8.00 
7.64 

Second  Fractionation. 


Lot. 

36 
36 
36 
36 
36 


Lot. 
51 
51 
51 


Lot. 
62 


Fraction. 

A 


d 


Fraction. 

A 
B 
C 


Fraction. 

A 


Per  cent. 

Per  cent. 

of  bromine 

of  bromine 

absorbed. 

Lot. 

Fraction. 

absorbed. 

4-74 

36 

D, 

6.81 

54° 

36 

A 

6.28 

5-66 

36 

EFl 

6-49 

5-56 

36 

HF2 

7.18 

6.18 

Third  Fractionation. 


Per  cent. 

of  bromine 

absorbed. 

3-27 


4-47 


Fourth  Fractionation. 

Per  cent, 
of  bromine 
absorbed.  Lot.          Fraction. 

2.86  62  E 


Per  cent. 

of  bromine 

Lot. 

Fraction. 

absorbed. 

51 

D 

4.92 

51 

E 

4.71 

51 

F 

5-36 

Per  cent, 
of  bromine 
absorbed. 

3-73 


These  results  demonstrate  conclusively  that  the  unsatura- 
ted  hydrocarbons  tend  to  collect  in  the  lower  sections  of  a 
layer  of  fuller's  earth  through  which  the  oil  is  allowed  to  dif- 
fuse. These  figures  confirm  the  results  obtained  by  Gilpin 
and  Cram  in  their  work  on  the  Pennsylvania  petroleum.  In 
their  investigation,  distillation  by  heat  was  employed  in  order 
to  obtain  fractions  that  could  be  readily  studied.  In  this 
work  the  relative  amounts  of  the  unsaturated  hydrocarbons 
in  the  various  oils  were  determined  directly  as  they  came 
from  the  earth. 

The  percentages  by  volume  of  oil  absorbed  by  concentra- 
ted sulphuric  acid  represent  only  approximately  the  per- 
centages of  unsaturated  hydrocarbons,  since,  as  was  shown 
previously,  any  benzene  which  may  have  been  present  in  the 
oils  was  also  removed  by  the  concentrated  acid.  This  fact 
rendered  impossible  a  quantitative  separation  of  the  aro- 
matic from  the  unsaturated  hydrocarbons.  Since  no  other 
methods,  besides  nitration  and  sulphonation,  neither  of  which 
could  be  here  employed,  were  available,  no  results  as  to  the 


52 

relative  amounts  of  the  aromatic  hydrocarbons  in  the  various 
fractions  could  be  obtained. 

It  is  evident  from  the  results  of  the  bromine  determina- 
tions that,  as  the  fractionation  proceeds,  the  amounts  of  un- 
saturated  hydrocarbons  become  smaller  and  smaller.  A 
comparison  of  the  amounts  of  bromine  absorbed  by  Fraction 
A  of  the  first,  second,  third  and  fourth  fractionations  is  given 
below  for  the  purpose  of  bringing  out  this  point  more  clearly : 

Per  Cent,  of  Bromine  Absorbed  by  Fraction  A. 

First  Second  Third  Fourth 

fractionation.         fractionation.  fractionation.  fractionation. 

5.02  4.74  3.27  2.86 

Sulphur  Compounds. — The  sulphur  in  the  various  oils  was 
determined  by  the  usual  method  of  combustion.  For  these 
determinations,  the  oils  obtained  from  one  tube  of  Lot  6  were 
employed.  The  results  are  given  in  the  following  table: 

Lot  6 
Fraction. 

A 
B 
C 

The  percentage  of  sulphur  in  the  Fractions  A,  C  and  E  of 
Lot  51  was  also  determined.  The  results  were  as  follows: 

Table  X.—Lot  51. 

Per  cent.  Per  cent. 

Fraction.  of  sulphur.  Fraction.  of  sulphur. 

A  0.003  ^  0.006 

C  o . 040 

These  results  show  that  the  sulphur  tends  to  collect  in  the 
oils  in  lower  sections  of  the  tube.  As  the  fractionation  pro- 
ceeds, the  proportion  of  sulphur  becomes  smaller.  The  fig- 
ures below  indicate  that  as  the  oil  is  subjected  to  repeated 
fractionations,  the  sulphur  is  gradually  removed: 

Per  Cent,  of  Sulphur. 

First  fractionation.  Second  fractionation.     Third  fractionation. 

Fraction  A      o .  04  ....  o .  003 

Fraction  E      0.16  ....  0.006 

Fraction  C  o .  08  o .  040 


Specific 

Per  cent. 

Lot  6. 

Specific 

Per  cent. 

gravity. 

sulphur. 

Fraction. 

gravity. 

sulphur. 

0.8195 

O.O4 

D 

0.8510 

O.O9 

0.8362 

0.05 

E 

o  .  8600 

o.  16 

o  .  8440 

Lost 

53 

Selective  Action  of  Fuller's  Earth. 

When  the  earth,  from  which  as  much  oil  as  possible  has  been 
extracted  by  prolonged  treatment  of  water,  is  dried,  and  then 
digested  with  ether,  oils  of  surprisingly  high  specific  gravity 
and  viscosity  are  obtained. 

In  the  experiments  undertaken  to  study  the  selective  ac- 
tion of  fuller's  earth,  the  procedure  was  as  follows:  The 
earth  under  examination  was  thoroughly  treated  with  water 
until  no  more  oil  appeared.  This  muddy  earth  of  the  consis- 
tency of  thin  liquid  paste  was  spread  upon  porous  plates  and 
allowed  to  dry  at  room  temperature.  Several  weeks  usually 
elapsed  before  the  earth  became  completely  dry.  It  was  then 
finely  pulverized,  and  after  being  thoroughly  soaked  and 
shaken  with  ether  the  mixture  was  allowed  to  remain  undis- 
turbed for  24  hours  or  more.  The  mixture  was  then  filtered 
and  the  dissolved  oil  recovered  by  distilling  off  the  ether 
from  the  filtrate.  The  residual  earth  was  then  digested  with 
ether  for  some  time  by  means  of  an  electric  stove  that  com- 
pletely surrounded  the  flask.  The  oil  thus  extracted  was  added 
to  the  oil  first  obtained.  In  several  cases  the  residual  earth 
was  treated  further  with  ether  in  the  Soxhlet  extractor. 

The  results  of  these  extractions  are  given  in  the  following 
table: 

Table  XL 

Speci 
crrax 

Lot.       Fraction. 

7  A 

8  A 
18  Al 

18  A2 

19  At 
19  A2 
19  Az 
25  ^i 
25  A2 

The  specific  gravity  of  none  of  the  oils  of  the  first  and  sec- 
ond fractionation,  extracted  with  ether,  except  those  of  Lot 
19,  could  be  determined  at  20°  C.  All  were  extremely  vis- 


Specific 
gravity 

Specific 
gravity 

at  50°. 

Lot. 

Fraction.             at  50°. 

o  .  8470 

25 

A3 

0.8391 

0.8502 

25 

B 

0.8489 

0.8419 

Specific  gravity  at  20°. 

o  .  8400 

51 

A 

0.8368 

0.8495 

51 

B 

0.8473 

0.8495 

51 

C 

0.8491 

O.86OO 

71 

D 

0.8568 

0-8363 

51 

E 

0.8518 

0.8381 

51 

F 

0-8553 

54 

cous;  those  of  Lot  25  were  so  viscous  at  this  temperature 
that  they  would  not  flow  when  the  bottles  containing  them 
were  inclined.  The  color  of  the  oils  ranges  from  brown  to 
black.  The  ethereal  solutions,  however,  of  many  of  the  oils 
were  very  light  in  color. 

It  is  interesting  to  compare  the  specific  gravities  of  the 
oils  extracted  with  ether  with  those  of  the  corresponding  oils 
extracted  with  water.  For  this  purpose,  the  oils  extracted 
by  water  and  by  ether  from  the  earth  of  Lot  51  are  chosen. 
In  the  table  below,  the  specific  gravities  of  these  oils  at  the 
same  temperature,  i.  e.,  20°,  are  given: 

Table  XII. — Lot  51.     Specific  Gravity  at  20°. 

Frac.  Ether.  Water.  Frac.  Ether.  Water. 

A  0.8368  0.8213  D  0.8568  0.8353 
B  0.8473  0.8303  E  0.8518  0.8366 
C  0.8491  0.8337  F  0.8553  0.8373 

As  the  figures  above  indicate,  the  specific  gravities  of  oils 
extracted  with  ether  are  much  higher  than  those  of  the  corre- 
sponding oils  extracted  with  water.  The  presence  of  such 
heavy  and  viscous  oils  in  the  upper  sections  of  the  tube  can  be 
explained  only  by  assuming  that  they  were  carried  to  these 
heights  in  solution  with  the  lighter  oils,  and  were  then  re- 
moved by  the  earth.  Since  such  viscous  oils  are  totally  un- 
able to  diffuse  by  capillarity  to  any  appreciable  extent,  it  is 
not  probable  that  their  transportation  to  the  upper  parts  of 
the  tube  was  effected  by  capillary  diffusion. 

Chemical   Examination   of   the   Oils   Extracted   by   Ether — Un- 
saturated  Hydrocarbons. 

Action,  of  Concentrated  Sulphuric  Acid. — The  percentage  by 
volume  of  oil  absorbed  by  concentrated  sulphuric  acid  (specific 
gravity  1.84)  was  determined  according  to  the  following  pro- 
cedure: Ten  cc.  of  the  oil  to  be  examined  were  measured  into 
a  glass-stoppered  bottle,  and  thirty  cc.  of  concentrated  sul- 
phuric acid  were  added.  The  mixture  was  thoroughly  shaken 
in  a  machine  for  30  minutes  and  then  poured  into  a  burette. 


55 

After  allowing  sufficient  time  for  any  oil  that  might  be  mechan- 
ically absorbed  in  the  acid  to  rise  to  the  top,  the  volume  of 
unabsorbable  oil  was  read  directly  over  the  acid.  Owing  to 
the  formation  of  heavy  emulsions,  no  attempt  was  made  to 
neutralize  and  wash  the  oil. 

The  oils  selected  for  examination  were  those  extracted  by 
ether  from  the  earth  of  Lots  36  and  51. 

The  results  of  the  analyses  are  given  in  the  following  table : 

Table  XIII. 


Oils 
extracted 
by  ether. 
Per  cent. 

Oils 
extracted 
by  water. 
Per  cent. 

Oils 
extracted 
by  ether. 
Per  cent. 

Oils 
extracted 
by  water. 
Per  cent. 

by  voli 

time 

by  vol 

urne 

by  voh 

ime 

by  vo 

lume 

Lot. 

Fraction. 

absorbed. 

absorbed. 

Lot. 

Fraction. 

absorbed. 

absorbed. 

36 

A 

24 

0 

3 

.0 

51 

c 

17 

.0 

9 

.  I 

36 

B 

37 

O 

10 

•4 

51 

D 

16 

•4 

ii 

•5 

51 

A 

7 

0 

2 

•3 

51 

E 

16 

•5 

12 

•5 

51 

B 

ii 

5 

6 

.  i 

51 

F 

18 

.0 

H 

•5 

Action  of  Bromine. — The  method  employed  for  determining 
the  amount  of  bromine  absorbed  by  the  oils  has  already  been 
described  (p.  50). 

The  amounts  of  bromine  absorbed,  calculated  upon  the 
basis  of  loo  grams  of  oil,  are  given  in  the  table  below.  The 
values  for  the  corresponding  oils  extracted  with  water  are 
also  given  for  comparison. 


Table  XIV. 


Oils  Oils 

extracted  extracted 

by  ether.         by  water. 

Per  cent.  Per  cent. 

of  bromine  of  bromine 


Oils  Oils  ex- 
extracted  tracted 

by  ether,  by  water. 

Per  cent.  Per  cent, 

of  bromine  of  bromine 


Lot. 

Fraction. 

absorbed. 

absorbed. 

Lot. 

Fraction. 

absorbed.       absorbe< 

32 

A 

5- 

30 

5 

02 

51 

B 

4 

•45 

4 

36 

32 

B 

7- 

39 

6. 

96 

51 

C 

6 

.27 

5 

03 

36 

A 

5 

72 

4 

74 

51 

D 

6 

.09 

4 

92 

36 

B 

6. 

10 

5 

40 

51 

E 

5 

.98 

4 

7i 

36 

C 

6. 

72 

5 

56 

51 

F 

5 

.20 

5 

36 

51 

A 

3 

.27 

3 

.27 

/ 

As  these  results  clearly  demonstrate,  fuller's  earth  retains 
the  unsaturated  hydrocarbons,  thus  exercising  a  selective 
action. 


56 

Sulphur  Compounds. — The  sulphur  in  the  oils  obtained  by 
extraction  with  ether  was  determined  by  the  usual  method 
of  combustion.  The  results  are  given  in  the  table  below: 

Table  XV. 


Oils  extrac- 

Oils extrac- 

Oils extrac- 

Oils extrac- 

ted by 

ted  by 

ted  by 

ted  by 

ether. 

water. 

ether. 

water. 

Per  cent. 

Per  cent. 

Per  cent. 

Per  cent. 

Lot.  51. 

of  sulphur. 

of  sulphur. 

Lot  51. 

of  sulphur. 

of  sulphur. 

A 

0.004 

0.003 

D 

0.060 

B 

O.OII 

E 

0.080 

C 

0.050 

0.040 

F 

O.OSO 

O.OO6 

The  selective  action  of  the  earth,  in  regard  to  the  sulphur 
compounds,  is  indicated  by  these  results.  This  fact  was  also 
pointed  out  by  Richardson  and  Wallace.  It  is  very  prob- 
able that  the  earth  also  retains  largely  the  nitrogen  compounds 
in  the  oil,  and  may  also  remove  to  a  greater  or  less  extent  the 
benzene  hydrocarbons. 

These  results  seem  to  furnish  evidence  in  favor  of  the  view 
that  the  Pennsylvania  oil  diffused,  at  some  time  in  the  history, 
through  porous  media,  which  exercised  a  selective  action  upon 
it,  removing  a  large  part  of  the  unsaturated  and  sulphur  com- 
pounds, and  probable  the  benzene  and  nitrogen  compound. 

SUMMARY. 

1.  When  a  solution  of  benzene  and  a  paraffin  oil  is  allowed 
to  diffuse  upward  through  a  tube  packed  with  fuller's  earth, 
the  benzene  tends  to  collect  in  the  lower  sections  and  the 
paraffin  oil  in  the  upper  sections  of  the  tube. 

2.  When  crude  petroleum  diffuses  upward  through  a  tube 
packed  with  fuller's  earth,  a  fractionation  of  the  oil  occurs. 
The  oil  that  is  displaced  by  water  from  the  earth  from  the 
top  of  the  tube  possesses  a  lower  specific  gravity  than  the  oil 
obtained  from  the  earth  at  the  bottom  of  the  tube. 

3.  As  the  fractionation  proceeds,  the  range  of  specific  grav- 
ity covered  in  succeeding  fractionations  becomes  smaller,  in- 
dicating  a   movement   towards   the   production   of   mixtures 
which  will  finally  pass  through  the  earth,  unaltered. 


57 

4.  In  the  fractionation  of  petroleum  by  capillary  diffusion 
through  fuller's  earth,  the  amounts  of  unsaturated  hydrocar- 
bons and  sulphur  compounds  in  the  resulting  fractions  in- 
crease gradually  from  the  lightest  oils  at  the  top  to  the  heavier 
oils  at  the  bottom  of  the  tube. 

5.  Fuller's  earth  tends  to  retain  the  unsaturated  hydrocar- 
bons and  sulphur  compounds  in  petroleum,  thus  exercising 
a  selective  action  upon  the  oil. 


BIOGRAPHICAL. 

The  author  of  this  dissertation,  Oscar  Ellis  Bransky,  was  born 
in  Baltimore,  January  29,  1886.  He  received  his  early  educa- 
tion in  the  public  schools  of  Baltimore.  In  1904,  he  graduated 
from  the  Baltimore  City  College,  and  in  October  of  the  same 
year  he  entered  the  Johns  Hopkins  University.  He  received 
the  degree  of  Bachelor  of  Arts  in  1907.  He  then  entered  the 
post-graduate  department  of  the  university,  pursuing  Chem- 
isty  as  his  major,  and  Physical  Chemistry  and  Geology  as  his 
minor  subjects.  During  1908-1909  he  acted  as  laboratory 
assistant  to  Professor  Renouf . 


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